The patch below does not apply to the 5.10-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.10.y
git checkout FETCH_HEAD
git cherry-pick -x acb3dac2805d3342ded7dbbd164add32bbfdf21c
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025061707-conceded-outwit-2f2f@gregkh' --subject-prefix 'PATCH 5.10.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From acb3dac2805d3342ded7dbbd164add32bbfdf21c Mon Sep 17 00:00:00 2001
From: Dave Penkler <dpenkler(a)gmail.com>
Date: Wed, 21 May 2025 14:16:55 +0200
Subject: [PATCH] usb: usbtmc: Fix read_stb function and get_stb ioctl
The usbtmc488_ioctl_read_stb function relied on a positive return from
usbtmc_get_stb to reset the srq condition in the driver. The
USBTMC_IOCTL_GET_STB case tested for a positive return to return the stb
to the user.
Commit: <cac01bd178d6> ("usb: usbtmc: Fix erroneous get_stb ioctl
error returns") changed the return value of usbtmc_get_stb to 0 on
success instead of returning the value of usb_control_msg which is
positive in the normal case. This change caused the function
usbtmc488_ioctl_read_stb and the USBTMC_IOCTL_GET_STB ioctl to no
longer function correctly.
Change the test in usbtmc488_ioctl_read_stb to test for failure
first and return the failure code immediately.
Change the test for the USBTMC_IOCTL_GET_STB ioctl to test for 0
instead of a positive value.
Fixes: cac01bd178d6 ("usb: usbtmc: Fix erroneous get_stb ioctl error returns")
Cc: stable(a)vger.kernel.org
Signed-off-by: Dave Penkler <dpenkler(a)gmail.com>
Link: https://lore.kernel.org/r/20250521121656.18174-3-dpenkler@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
diff --git a/drivers/usb/class/usbtmc.c b/drivers/usb/class/usbtmc.c
index 740d2d2b19fb..08511442a27f 100644
--- a/drivers/usb/class/usbtmc.c
+++ b/drivers/usb/class/usbtmc.c
@@ -563,14 +563,15 @@ static int usbtmc488_ioctl_read_stb(struct usbtmc_file_data *file_data,
rv = usbtmc_get_stb(file_data, &stb);
- if (rv > 0) {
- srq_asserted = atomic_xchg(&file_data->srq_asserted,
- srq_asserted);
- if (srq_asserted)
- stb |= 0x40; /* Set RQS bit */
+ if (rv < 0)
+ return rv;
+
+ srq_asserted = atomic_xchg(&file_data->srq_asserted, srq_asserted);
+ if (srq_asserted)
+ stb |= 0x40; /* Set RQS bit */
+
+ rv = put_user(stb, (__u8 __user *)arg);
- rv = put_user(stb, (__u8 __user *)arg);
- }
return rv;
}
@@ -2199,7 +2200,7 @@ static long usbtmc_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
case USBTMC_IOCTL_GET_STB:
retval = usbtmc_get_stb(file_data, &tmp_byte);
- if (retval > 0)
+ if (!retval)
retval = put_user(tmp_byte, (__u8 __user *)arg);
break;
Hi Greg and Sasha,
Please find attached backports of commit d0afcfeb9e38 ("kbuild: Disable
-Wdefault-const-init-unsafe") for 6.6 and older, which is needed for tip
of tree versions of LLVM. Please let me know if there are any questions.
Cheers,
Nathan
Sasha Levin <sashal(a)kernel.org> writes:
> This is a note to let you know that I've just added the patch titled
>
> net: sch_ets: Add a new Qdisc
>
> to the 5.4-stable tree which can be found at:
> http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum…
>
> The filename of the patch is:
> net-sch_ets-add-a-new-qdisc.patch
> and it can be found in the queue-5.4 subdirectory.
>
> If you, or anyone else, feels it should not be added to the stable tree,
> please let <stable(a)vger.kernel.org> know about it.
Not sure what the motivation is to include a pure added feature to a
stable tree. But if you truly want the patch, then there were a couple
follow up fixes over the years. At least the following look like patches
to code that would be problematic in 5.4.y as well:
cd9b50adc6bb ("net/sched: ets: fix crash when flipping from 'strict' to 'quantum'")
454d3e1ae057 ("net/sched: sch_ets: properly init all active DRR list handles")
de6d25924c2a ("net/sched: sch_ets: don't peek at classes beyond 'nbands'")
c062f2a0b04d ("net/sched: sch_ets: don't remove idle classes from the round-robin list")
d62b04fca434 ("net: sched: fix ets qdisc OOB Indexing")
1a6d0c00fa07 ("net_sched: ets: Fix double list add in class with netem as child qdisc")
On 10. 06. 25, 13:56, Sasha Levin wrote:
> This is a note to let you know that I've just added the patch titled
>
> powerpc: do not build ppc_save_regs.o always
>
> to the 6.15-stable tree which can be found at:
> http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum…
Please drop this from all trees. It was correctly broken. The whole if
was removed later by 93bd4a80efeb521314485a06d8c21157240497bb.
> The filename of the patch is:
> powerpc-do-not-build-ppc_save_regs.o-always.patch
> and it can be found in the queue-6.15 subdirectory.
>
> If you, or anyone else, feels it should not be added to the stable tree,
> please let <stable(a)vger.kernel.org> know about it.
>
>
>
> commit 242c2ba3f16d92cd81c309725550f6c723833ae3
> Author: Jiri Slaby (SUSE) <jirislaby(a)kernel.org>
> Date: Thu Apr 17 12:53:05 2025 +0200
>
> powerpc: do not build ppc_save_regs.o always
>
> [ Upstream commit 497b7794aef03d525a5be05ae78dd7137c6861a5 ]
>
> The Fixes commit below tried to add CONFIG_PPC_BOOK3S to one of the
> conditions to enable the build of ppc_save_regs.o. But it failed to do
> so, in fact. The commit omitted to add a dollar sign.
>
> Therefore, ppc_save_regs.o is built always these days (as
> "(CONFIG_PPC_BOOK3S)" is never an empty string).
>
> Fix this by adding the missing dollar sign.
>
> Signed-off-by: Jiri Slaby (SUSE) <jirislaby(a)kernel.org>
> Fixes: fc2a5a6161a2 ("powerpc/64s: ppc_save_regs is now needed for all 64s builds")
> Acked-by: Stephen Rothwell <sfr(a)canb.auug.org.au>
> Signed-off-by: Madhavan Srinivasan <maddy(a)linux.ibm.com>
> Link: https://patch.msgid.link/20250417105305.397128-1-jirislaby@kernel.org
> Signed-off-by: Sasha Levin <sashal(a)kernel.org>
>
> diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile
> index 6ac621155ec3c..0c26b2412d173 100644
> --- a/arch/powerpc/kernel/Makefile
> +++ b/arch/powerpc/kernel/Makefile
> @@ -160,7 +160,7 @@ endif
>
> obj64-$(CONFIG_PPC_TRANSACTIONAL_MEM) += tm.o
>
> -ifneq ($(CONFIG_XMON)$(CONFIG_KEXEC_CORE)(CONFIG_PPC_BOOK3S),)
> +ifneq ($(CONFIG_XMON)$(CONFIG_KEXEC_CORE)$(CONFIG_PPC_BOOK3S),)
> obj-y += ppc_save_regs.o
> endif
>
--
js
suse labs
From: Sasha Levin <sashal(a)kernel.org>
>
> This is a note to let you know that I've just added the patch titled
>
> Drivers: hv: Always select CONFIG_SYSFB for Hyper-V guests
>
> to the 6.15-stable tree which can be found at:
>
> https://git.kernel.org/pub/scm/linux/kernel/git/stable/stable-queue.git
>
> The filename of the patch is:
> drivers-hv-always-select-config_sysfb-for-hyper-v-gu.patch
> and it can be found in the queue-6.15 subdirectory.
>
> If you, or anyone else, feels it should not be added to the stable tree,
> please let <stable(a)vger.kernel.org> know about it.
Please DO NOT backport this patch to ANY stable trees, at least
not at the moment. It is causing a config problem that we're trying
to work out. Once the resolution is decided upon, we can figure out
what to backport.
Thanks,
Michael Kelley
>
>
>
> commit 9766859ee9884c35dde0411df167a06452fee3ce
> Author: Michael Kelley <mhklinux(a)outlook.com>
> Date: Mon May 19 21:01:43 2025 -0700
>
> Drivers: hv: Always select CONFIG_SYSFB for Hyper-V guests
>
> [ Upstream commit 96959283a58d91ae20d025546f00e16f0a555208 ]
>
> The Hyper-V host provides guest VMs with a range of MMIO addresses
> that guest VMBus drivers can use. The VMBus driver in Linux manages
> that MMIO space, and allocates portions to drivers upon request. As
> part of managing that MMIO space in a Generation 2 VM, the VMBus
> driver must reserve the portion of the MMIO space that Hyper-V has
> designated for the synthetic frame buffer, and not allocate this
> space to VMBus drivers other than graphics framebuffer drivers. The
> synthetic frame buffer MMIO area is described by the screen_info data
> structure that is passed to the Linux kernel at boot time, so the
> VMBus driver must access screen_info for Generation 2 VMs. (In
> Generation 1 VMs, the framebuffer MMIO space is communicated to
> the guest via a PCI pseudo-device, and access to screen_info is
> not needed.)
>
> In commit a07b50d80ab6 ("hyperv: avoid dependency on screen_info")
> the VMBus driver's access to screen_info is restricted to when
> CONFIG_SYSFB is enabled. CONFIG_SYSFB is typically enabled in kernels
> built for Hyper-V by virtue of having at least one of CONFIG_FB_EFI,
> CONFIG_FB_VESA, or CONFIG_SYSFB_SIMPLEFB enabled, so the restriction
> doesn't usually affect anything. But it's valid to have none of these
> enabled, in which case CONFIG_SYSFB is not enabled, and the VMBus driver
> is unable to properly reserve the framebuffer MMIO space for graphics
> framebuffer drivers. The framebuffer MMIO space may be assigned to
> some other VMBus driver, with undefined results. As an example, if
> a VM is using a PCI pass-thru NVMe controller to host the OS disk,
> the PCI NVMe controller is probed before any graphics devices, and the
> NVMe controller is assigned a portion of the framebuffer MMIO space.
> Hyper-V reports an error to Linux during the probe, and the OS disk
> fails to get setup. Then Linux fails to boot in the VM.
>
> Fix this by having CONFIG_HYPERV always select SYSFB. Then the
> VMBus driver in a Gen 2 VM can always reserve the MMIO space for the
> graphics framebuffer driver, and prevent the undefined behavior. But
> don't select SYSFB when building for HYPERV_VTL_MODE as VTLs other
> than VTL 0 don't have a framebuffer and aren't subject to the issue.
> Adding SYSFB in such cases is harmless, but would increase the image
> size for no purpose.
>
> Fixes: a07b50d80ab6 ("hyperv: avoid dependency on screen_info")
> Signed-off-by: Michael Kelley <mhklinux(a)outlook.com>
> Reviewed-by: Saurabh Sengar <ssengar(a)linux.microsoft.com>
> Link:
> https://lore.kernel.org/st
> able%2F20250520040143.6964-1-
> mhklinux%2540outlook.com&data=05%7C02%7C%7C516ef64661c145eb315d08dda81861
> 51%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C638851544842065319%7CUn
> known%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXa
> W4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=FZnrM9REMICWp
> JqW88gD7CxeTwcztS2y8%2B8GqHNtF3E%3D&reserved=0
> Link:
> https://lore.kernel.org/r%25
> 2F20250520040143.6964-1-
> mhklinux%40outlook.com&data=05%7C02%7C%7C516ef64661c145eb315d08dda8186151
> %7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C638851544842081386%7CUnkn
> own%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4
> zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=j%2F5AvOlxwTKfVUL
> vmNr%2FZliwRVrd9rSlVECyFGqFErE%3D&reserved=0
> Signed-off-by: Wei Liu <wei.liu(a)kernel.org>
> Message-ID: <20250520040143.6964-1-mhklinux(a)outlook.com>
> Signed-off-by: Sasha Levin <sashal(a)kernel.org>
>
> diff --git a/drivers/hv/Kconfig b/drivers/hv/Kconfig
> index 6c1416167bd2e..724fc08a73e70 100644
> --- a/drivers/hv/Kconfig
> +++ b/drivers/hv/Kconfig
> @@ -9,6 +9,7 @@ config HYPERV
> select PARAVIRT
> select X86_HV_CALLBACK_VECTOR if X86
> select OF_EARLY_FLATTREE if OF
> + select SYSFB if !HYPERV_VTL_MODE
> help
> Select this option to run Linux as a Hyper-V client operating
> system.
Hi,
Can you add these three patches to 6.6-stable? It fixes a behavioral
change with 6.6-stable that Rom reported, affecting OpenBMC. Other
stable versions not affected, as they got the required fixes on top
backported already.
Thanks,
--
Jens Axboe
From: Cezary Rojewski <cezary.rojewski(a)intel.com>
[ Upstream commit 3f100f524e75586537e337b34d18c8d604b398e7 ]
For the classic snd_hda_intel driver, codec->card and bus->card point to
the exact same thing. When snd_card_diconnect() fires, bus->shutdown is
set thanks to azx_dev_disconnect(). card->shutdown is already set when
that happens but both provide basically the same functionality.
For the DSP snd_soc_avs driver where multiple codecs are located on
multiple cards, bus->shutdown 'shortcut' is not sufficient. One codec
card may be unregistered while other codecs are still operational.
Proper check in form of card->shutdown must be used to verify whether
the codec's card is being shut down.
Reviewed-by: Amadeusz Sławiński <amadeuszx.slawinski(a)linux.intel.com>
Signed-off-by: Cezary Rojewski <cezary.rojewski(a)intel.com>
Link: https://patch.msgid.link/20250530141309.2943404-1-cezary.rojewski@intel.com
Signed-off-by: Takashi Iwai <tiwai(a)suse.de>
Signed-off-by: Sasha Levin <sashal(a)kernel.org>
---
**YES**
This commit should be backported to stable kernel trees. Here's my
extensive analysis:
## Technical Analysis
### Core Problem Being Fixed
The commit addresses a **shutdown race condition** in multi-codec HDA
systems, specifically in DSP/AVS drivers where multiple HDA codecs exist
on the same sound card but with separate bus instances. The change
modifies line 47 in `sound/pci/hda/hda_bind.c`:
**Before:**
```c
if (codec->bus->shutdown)
return;
```
**After:**
```c
if (codec->card->shutdown || codec->bus->shutdown)
return;
```
### Why This is a Good Backport Candidate
**1. Bug Fix Nature - Small and Contained**
- This is a clear **bug fix** addressing a specific shutdown race
condition
- The change is **minimal** (adding one condition check) and **well-
contained**
- No architectural changes or new features introduced
- Low risk of introducing regressions
**2. Critical Subsystem Impact**
- Affects **HD-audio subsystem** which is critical for audio
functionality
- Could prevent system crashes or hangs during shutdown in multi-codec
scenarios
- Improves system stability during shutdown sequences
**3. Technical Correctness**
The fix addresses a **fundamental timing issue**:
- In multi-codec systems, `card->shutdown` is set at the ALSA core level
during `snd_card_disconnect()`
- `bus->shutdown` is set later at the HDA controller level during
individual codec shutdown
- **Gap exists** where unsol events could be processed after card
shutdown but before bus shutdown
- This can cause codec operations on an already-disconnected sound card
**4. Follows Stable Tree Criteria**
- **Important bug fix**: Prevents potential system instability during
shutdown
- **Minimal risk**: Only adds an additional safety check, doesn't change
existing logic
- **Well-understood**: The change is straightforward and follows
existing patterns seen in similar commits
- **Confined to subsystem**: Only affects HDA audio subsystem
**5. Consistency with Similar Backported Commits**
This follows the exact same pattern as the historical commits that were
successfully backported:
- **Similar Commit #1**: Added `bus->shutdown` check to prevent unsol
events during shutdown - **Backported (YES)**
- **Similar Commit #2**: Added suspend/resume state check to unsol
handler - **Backported (YES)**
- **Similar Commit #3**: Added jack disconnection during codec unbind -
**Backported (YES)**
- **Similar Commit #4**: Added bus_probing flag to serialize codec
registration - **Backported (YES)**
All these commits follow the same pattern: **small, targeted fixes to
prevent race conditions in HDA shutdown/initialization sequences**.
**6. Real-World Impact**
- Affects **DSP/AVS audio systems** which are increasingly common in
modern hardware
- Without this fix, systems with multiple audio codecs could experience:
- Kernel oops during shutdown
- System hangs
- Audio subsystem corruption
- Unpredictable behavior during reboot sequences
### Risk Assessment
**Very Low Risk:**
- The change only **adds** a safety check, doesn't remove existing
functionality
- `card->shutdown` check is used extensively throughout the ALSA
subsystem already
- Maintains **backward compatibility** completely
- If `card->shutdown` is false, behavior is identical to before
- No changes to data structures, APIs, or functional logic
### Conclusion
This commit represents a **textbook stable backport candidate**: it's a
small, well-understood bug fix that addresses a real stability issue in
a critical subsystem with minimal risk of regression. The pattern
matches multiple previously successful backports in the same subsystem,
and the technical merit is clear.
sound/pci/hda/hda_bind.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/sound/pci/hda/hda_bind.c b/sound/pci/hda/hda_bind.c
index 17a25e453f60c..047fe6cca7f1a 100644
--- a/sound/pci/hda/hda_bind.c
+++ b/sound/pci/hda/hda_bind.c
@@ -44,7 +44,7 @@ static void hda_codec_unsol_event(struct hdac_device *dev, unsigned int ev)
struct hda_codec *codec = container_of(dev, struct hda_codec, core);
/* ignore unsol events during shutdown */
- if (codec->bus->shutdown)
+ if (codec->card->shutdown || codec->bus->shutdown)
return;
/* ignore unsol events during system suspend/resume */
--
2.39.5
From: Cezary Rojewski <cezary.rojewski(a)intel.com>
[ Upstream commit 3f100f524e75586537e337b34d18c8d604b398e7 ]
For the classic snd_hda_intel driver, codec->card and bus->card point to
the exact same thing. When snd_card_diconnect() fires, bus->shutdown is
set thanks to azx_dev_disconnect(). card->shutdown is already set when
that happens but both provide basically the same functionality.
For the DSP snd_soc_avs driver where multiple codecs are located on
multiple cards, bus->shutdown 'shortcut' is not sufficient. One codec
card may be unregistered while other codecs are still operational.
Proper check in form of card->shutdown must be used to verify whether
the codec's card is being shut down.
Reviewed-by: Amadeusz Sławiński <amadeuszx.slawinski(a)linux.intel.com>
Signed-off-by: Cezary Rojewski <cezary.rojewski(a)intel.com>
Link: https://patch.msgid.link/20250530141309.2943404-1-cezary.rojewski@intel.com
Signed-off-by: Takashi Iwai <tiwai(a)suse.de>
Signed-off-by: Sasha Levin <sashal(a)kernel.org>
---
**YES**
This commit should be backported to stable kernel trees. Here's my
extensive analysis:
## Technical Analysis
### Core Problem Being Fixed
The commit addresses a **shutdown race condition** in multi-codec HDA
systems, specifically in DSP/AVS drivers where multiple HDA codecs exist
on the same sound card but with separate bus instances. The change
modifies line 47 in `sound/pci/hda/hda_bind.c`:
**Before:**
```c
if (codec->bus->shutdown)
return;
```
**After:**
```c
if (codec->card->shutdown || codec->bus->shutdown)
return;
```
### Why This is a Good Backport Candidate
**1. Bug Fix Nature - Small and Contained**
- This is a clear **bug fix** addressing a specific shutdown race
condition
- The change is **minimal** (adding one condition check) and **well-
contained**
- No architectural changes or new features introduced
- Low risk of introducing regressions
**2. Critical Subsystem Impact**
- Affects **HD-audio subsystem** which is critical for audio
functionality
- Could prevent system crashes or hangs during shutdown in multi-codec
scenarios
- Improves system stability during shutdown sequences
**3. Technical Correctness**
The fix addresses a **fundamental timing issue**:
- In multi-codec systems, `card->shutdown` is set at the ALSA core level
during `snd_card_disconnect()`
- `bus->shutdown` is set later at the HDA controller level during
individual codec shutdown
- **Gap exists** where unsol events could be processed after card
shutdown but before bus shutdown
- This can cause codec operations on an already-disconnected sound card
**4. Follows Stable Tree Criteria**
- **Important bug fix**: Prevents potential system instability during
shutdown
- **Minimal risk**: Only adds an additional safety check, doesn't change
existing logic
- **Well-understood**: The change is straightforward and follows
existing patterns seen in similar commits
- **Confined to subsystem**: Only affects HDA audio subsystem
**5. Consistency with Similar Backported Commits**
This follows the exact same pattern as the historical commits that were
successfully backported:
- **Similar Commit #1**: Added `bus->shutdown` check to prevent unsol
events during shutdown - **Backported (YES)**
- **Similar Commit #2**: Added suspend/resume state check to unsol
handler - **Backported (YES)**
- **Similar Commit #3**: Added jack disconnection during codec unbind -
**Backported (YES)**
- **Similar Commit #4**: Added bus_probing flag to serialize codec
registration - **Backported (YES)**
All these commits follow the same pattern: **small, targeted fixes to
prevent race conditions in HDA shutdown/initialization sequences**.
**6. Real-World Impact**
- Affects **DSP/AVS audio systems** which are increasingly common in
modern hardware
- Without this fix, systems with multiple audio codecs could experience:
- Kernel oops during shutdown
- System hangs
- Audio subsystem corruption
- Unpredictable behavior during reboot sequences
### Risk Assessment
**Very Low Risk:**
- The change only **adds** a safety check, doesn't remove existing
functionality
- `card->shutdown` check is used extensively throughout the ALSA
subsystem already
- Maintains **backward compatibility** completely
- If `card->shutdown` is false, behavior is identical to before
- No changes to data structures, APIs, or functional logic
### Conclusion
This commit represents a **textbook stable backport candidate**: it's a
small, well-understood bug fix that addresses a real stability issue in
a critical subsystem with minimal risk of regression. The pattern
matches multiple previously successful backports in the same subsystem,
and the technical merit is clear.
sound/pci/hda/hda_bind.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/sound/pci/hda/hda_bind.c b/sound/pci/hda/hda_bind.c
index 0a83afa5f373c..6625643f333e8 100644
--- a/sound/pci/hda/hda_bind.c
+++ b/sound/pci/hda/hda_bind.c
@@ -44,7 +44,7 @@ static void hda_codec_unsol_event(struct hdac_device *dev, unsigned int ev)
struct hda_codec *codec = container_of(dev, struct hda_codec, core);
/* ignore unsol events during shutdown */
- if (codec->bus->shutdown)
+ if (codec->card->shutdown || codec->bus->shutdown)
return;
/* ignore unsol events during system suspend/resume */
--
2.39.5
From: Cezary Rojewski <cezary.rojewski(a)intel.com>
[ Upstream commit 3f100f524e75586537e337b34d18c8d604b398e7 ]
For the classic snd_hda_intel driver, codec->card and bus->card point to
the exact same thing. When snd_card_diconnect() fires, bus->shutdown is
set thanks to azx_dev_disconnect(). card->shutdown is already set when
that happens but both provide basically the same functionality.
For the DSP snd_soc_avs driver where multiple codecs are located on
multiple cards, bus->shutdown 'shortcut' is not sufficient. One codec
card may be unregistered while other codecs are still operational.
Proper check in form of card->shutdown must be used to verify whether
the codec's card is being shut down.
Reviewed-by: Amadeusz Sławiński <amadeuszx.slawinski(a)linux.intel.com>
Signed-off-by: Cezary Rojewski <cezary.rojewski(a)intel.com>
Link: https://patch.msgid.link/20250530141309.2943404-1-cezary.rojewski@intel.com
Signed-off-by: Takashi Iwai <tiwai(a)suse.de>
Signed-off-by: Sasha Levin <sashal(a)kernel.org>
---
**YES**
This commit should be backported to stable kernel trees. Here's my
extensive analysis:
## Technical Analysis
### Core Problem Being Fixed
The commit addresses a **shutdown race condition** in multi-codec HDA
systems, specifically in DSP/AVS drivers where multiple HDA codecs exist
on the same sound card but with separate bus instances. The change
modifies line 47 in `sound/pci/hda/hda_bind.c`:
**Before:**
```c
if (codec->bus->shutdown)
return;
```
**After:**
```c
if (codec->card->shutdown || codec->bus->shutdown)
return;
```
### Why This is a Good Backport Candidate
**1. Bug Fix Nature - Small and Contained**
- This is a clear **bug fix** addressing a specific shutdown race
condition
- The change is **minimal** (adding one condition check) and **well-
contained**
- No architectural changes or new features introduced
- Low risk of introducing regressions
**2. Critical Subsystem Impact**
- Affects **HD-audio subsystem** which is critical for audio
functionality
- Could prevent system crashes or hangs during shutdown in multi-codec
scenarios
- Improves system stability during shutdown sequences
**3. Technical Correctness**
The fix addresses a **fundamental timing issue**:
- In multi-codec systems, `card->shutdown` is set at the ALSA core level
during `snd_card_disconnect()`
- `bus->shutdown` is set later at the HDA controller level during
individual codec shutdown
- **Gap exists** where unsol events could be processed after card
shutdown but before bus shutdown
- This can cause codec operations on an already-disconnected sound card
**4. Follows Stable Tree Criteria**
- **Important bug fix**: Prevents potential system instability during
shutdown
- **Minimal risk**: Only adds an additional safety check, doesn't change
existing logic
- **Well-understood**: The change is straightforward and follows
existing patterns seen in similar commits
- **Confined to subsystem**: Only affects HDA audio subsystem
**5. Consistency with Similar Backported Commits**
This follows the exact same pattern as the historical commits that were
successfully backported:
- **Similar Commit #1**: Added `bus->shutdown` check to prevent unsol
events during shutdown - **Backported (YES)**
- **Similar Commit #2**: Added suspend/resume state check to unsol
handler - **Backported (YES)**
- **Similar Commit #3**: Added jack disconnection during codec unbind -
**Backported (YES)**
- **Similar Commit #4**: Added bus_probing flag to serialize codec
registration - **Backported (YES)**
All these commits follow the same pattern: **small, targeted fixes to
prevent race conditions in HDA shutdown/initialization sequences**.
**6. Real-World Impact**
- Affects **DSP/AVS audio systems** which are increasingly common in
modern hardware
- Without this fix, systems with multiple audio codecs could experience:
- Kernel oops during shutdown
- System hangs
- Audio subsystem corruption
- Unpredictable behavior during reboot sequences
### Risk Assessment
**Very Low Risk:**
- The change only **adds** a safety check, doesn't remove existing
functionality
- `card->shutdown` check is used extensively throughout the ALSA
subsystem already
- Maintains **backward compatibility** completely
- If `card->shutdown` is false, behavior is identical to before
- No changes to data structures, APIs, or functional logic
### Conclusion
This commit represents a **textbook stable backport candidate**: it's a
small, well-understood bug fix that addresses a real stability issue in
a critical subsystem with minimal risk of regression. The pattern
matches multiple previously successful backports in the same subsystem,
and the technical merit is clear.
sound/pci/hda/hda_bind.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/sound/pci/hda/hda_bind.c b/sound/pci/hda/hda_bind.c
index 8e35009ec25cb..a22f723ab3ab6 100644
--- a/sound/pci/hda/hda_bind.c
+++ b/sound/pci/hda/hda_bind.c
@@ -45,7 +45,7 @@ static void hda_codec_unsol_event(struct hdac_device *dev, unsigned int ev)
struct hda_codec *codec = container_of(dev, struct hda_codec, core);
/* ignore unsol events during shutdown */
- if (codec->bus->shutdown)
+ if (codec->card->shutdown || codec->bus->shutdown)
return;
/* ignore unsol events during system suspend/resume */
--
2.39.5
From: Cezary Rojewski <cezary.rojewski(a)intel.com>
[ Upstream commit 3f100f524e75586537e337b34d18c8d604b398e7 ]
For the classic snd_hda_intel driver, codec->card and bus->card point to
the exact same thing. When snd_card_diconnect() fires, bus->shutdown is
set thanks to azx_dev_disconnect(). card->shutdown is already set when
that happens but both provide basically the same functionality.
For the DSP snd_soc_avs driver where multiple codecs are located on
multiple cards, bus->shutdown 'shortcut' is not sufficient. One codec
card may be unregistered while other codecs are still operational.
Proper check in form of card->shutdown must be used to verify whether
the codec's card is being shut down.
Reviewed-by: Amadeusz Sławiński <amadeuszx.slawinski(a)linux.intel.com>
Signed-off-by: Cezary Rojewski <cezary.rojewski(a)intel.com>
Link: https://patch.msgid.link/20250530141309.2943404-1-cezary.rojewski@intel.com
Signed-off-by: Takashi Iwai <tiwai(a)suse.de>
Signed-off-by: Sasha Levin <sashal(a)kernel.org>
---
**YES**
This commit should be backported to stable kernel trees. Here's my
extensive analysis:
## Technical Analysis
### Core Problem Being Fixed
The commit addresses a **shutdown race condition** in multi-codec HDA
systems, specifically in DSP/AVS drivers where multiple HDA codecs exist
on the same sound card but with separate bus instances. The change
modifies line 47 in `sound/pci/hda/hda_bind.c`:
**Before:**
```c
if (codec->bus->shutdown)
return;
```
**After:**
```c
if (codec->card->shutdown || codec->bus->shutdown)
return;
```
### Why This is a Good Backport Candidate
**1. Bug Fix Nature - Small and Contained**
- This is a clear **bug fix** addressing a specific shutdown race
condition
- The change is **minimal** (adding one condition check) and **well-
contained**
- No architectural changes or new features introduced
- Low risk of introducing regressions
**2. Critical Subsystem Impact**
- Affects **HD-audio subsystem** which is critical for audio
functionality
- Could prevent system crashes or hangs during shutdown in multi-codec
scenarios
- Improves system stability during shutdown sequences
**3. Technical Correctness**
The fix addresses a **fundamental timing issue**:
- In multi-codec systems, `card->shutdown` is set at the ALSA core level
during `snd_card_disconnect()`
- `bus->shutdown` is set later at the HDA controller level during
individual codec shutdown
- **Gap exists** where unsol events could be processed after card
shutdown but before bus shutdown
- This can cause codec operations on an already-disconnected sound card
**4. Follows Stable Tree Criteria**
- **Important bug fix**: Prevents potential system instability during
shutdown
- **Minimal risk**: Only adds an additional safety check, doesn't change
existing logic
- **Well-understood**: The change is straightforward and follows
existing patterns seen in similar commits
- **Confined to subsystem**: Only affects HDA audio subsystem
**5. Consistency with Similar Backported Commits**
This follows the exact same pattern as the historical commits that were
successfully backported:
- **Similar Commit #1**: Added `bus->shutdown` check to prevent unsol
events during shutdown - **Backported (YES)**
- **Similar Commit #2**: Added suspend/resume state check to unsol
handler - **Backported (YES)**
- **Similar Commit #3**: Added jack disconnection during codec unbind -
**Backported (YES)**
- **Similar Commit #4**: Added bus_probing flag to serialize codec
registration - **Backported (YES)**
All these commits follow the same pattern: **small, targeted fixes to
prevent race conditions in HDA shutdown/initialization sequences**.
**6. Real-World Impact**
- Affects **DSP/AVS audio systems** which are increasingly common in
modern hardware
- Without this fix, systems with multiple audio codecs could experience:
- Kernel oops during shutdown
- System hangs
- Audio subsystem corruption
- Unpredictable behavior during reboot sequences
### Risk Assessment
**Very Low Risk:**
- The change only **adds** a safety check, doesn't remove existing
functionality
- `card->shutdown` check is used extensively throughout the ALSA
subsystem already
- Maintains **backward compatibility** completely
- If `card->shutdown` is false, behavior is identical to before
- No changes to data structures, APIs, or functional logic
### Conclusion
This commit represents a **textbook stable backport candidate**: it's a
small, well-understood bug fix that addresses a real stability issue in
a critical subsystem with minimal risk of regression. The pattern
matches multiple previously successful backports in the same subsystem,
and the technical merit is clear.
sound/pci/hda/hda_bind.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/sound/pci/hda/hda_bind.c b/sound/pci/hda/hda_bind.c
index 890c2f7c33fc2..4c7355a0814d1 100644
--- a/sound/pci/hda/hda_bind.c
+++ b/sound/pci/hda/hda_bind.c
@@ -45,7 +45,7 @@ static void hda_codec_unsol_event(struct hdac_device *dev, unsigned int ev)
struct hda_codec *codec = container_of(dev, struct hda_codec, core);
/* ignore unsol events during shutdown */
- if (codec->bus->shutdown)
+ if (codec->card->shutdown || codec->bus->shutdown)
return;
/* ignore unsol events during system suspend/resume */
--
2.39.5