From: Baochen Qiang <bqiang(a)codeaurora.org>
During system resume, MHI host triggers M3->M0 transition and then waits
for target device to enter M0 state. Once done, the device queues a state
change event into ctrl event ring and notifies MHI host by raising an
interrupt, where a tasklet is scheduled to process this event. In most
cases, the tasklet is served timely and wait operation succeeds.
However, there are cases where CPU is busy and cannot serve this tasklet
for some time. Once delay goes long enough, the device moves itself to M1
state and also interrupts MHI host after inserting a new state change
event to ctrl ring. Later when CPU finally has time to process the ring,
there will be two events:
1. For M3->M0 event, which is the first event to be processed queued first.
The tasklet handler serves the event, updates device state to M0 and
wakes up the task.
2. For M0->M1 event, which is processed later, the tasklet handler
triggers M1->M2 transition and updates device state to M2 directly,
then wakes up the MHI host (if it is still sleeping on this wait queue).
Note that although MHI host has been woken up while processing the first
event, it may still has no chance to run before the second event is
processed. In other words, MHI host has to keep waiting till timeout
causing the M0 state to be missed.
kernel log here:
...
Apr 15 01:45:14 test-NUC8i7HVK kernel: [ 4247.911251] mhi 0000:06:00.0: Entered with PM state: M3, MHI state: M3
Apr 15 01:45:14 test-NUC8i7HVK kernel: [ 4247.917762] mhi 0000:06:00.0: State change event to state: M0
Apr 15 01:45:14 test-NUC8i7HVK kernel: [ 4247.917767] mhi 0000:06:00.0: State change event to state: M1
Apr 15 01:45:14 test-NUC8i7HVK kernel: [ 4338.788231] mhi 0000:06:00.0: Did not enter M0 state, MHI state: M2, PM state: M2
...
Fix this issue by simply adding M2 as a valid state for resume.
Tested-on: WCN6855 hw2.0 PCI WLAN.HSP.1.1-01720.1-QCAHSPSWPL_V1_V2_SILICONZ_LITE-1
Cc: stable(a)vger.kernel.org
Fixes: 0c6b20a1d720 ("bus: mhi: core: Add support for MHI suspend and resume")
Signed-off-by: Baochen Qiang <bqiang(a)codeaurora.org>
Reviewed-by: Hemant Kumar <hemantk(a)codeaurora.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam(a)linaro.org>
Link: https://lore.kernel.org/r/20210524040312.14409-1-bqiang@codeaurora.org
[mani: slightly massaged the commit message]
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam(a)linaro.org>
---
drivers/bus/mhi/core/pm.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/bus/mhi/core/pm.c b/drivers/bus/mhi/core/pm.c
index 704a5e225097..bbf6cd04861e 100644
--- a/drivers/bus/mhi/core/pm.c
+++ b/drivers/bus/mhi/core/pm.c
@@ -926,6 +926,7 @@ int mhi_pm_resume(struct mhi_controller *mhi_cntrl)
ret = wait_event_timeout(mhi_cntrl->state_event,
mhi_cntrl->dev_state == MHI_STATE_M0 ||
+ mhi_cntrl->dev_state == MHI_STATE_M2 ||
MHI_PM_IN_ERROR_STATE(mhi_cntrl->pm_state),
msecs_to_jiffies(mhi_cntrl->timeout_ms));
--
2.25.1
From: Loic Poulain <loic.poulain(a)linaro.org>
On graceful power-down/disable transition, when an MHI reset is
performed, the MHI device loses its context, including interrupt
configuration. However, the current implementation is waiting for
event(irq) driven state change to confirm reset has been completed,
which never happens, and causes reset timeout, leading to unexpected
high latency of the mhi_power_down procedure (up to 45 seconds).
Fix that by moving to the recently introduced poll_reg_field method,
waiting for the reset bit to be cleared, in the same way as the
power_on procedure.
Cc: stable(a)vger.kernel.org
Fixes: a6e2e3522f29 ("bus: mhi: core: Add support for PM state transitions")
Signed-off-by: Loic Poulain <loic.poulain(a)linaro.org>
Reviewed-by: Bhaumik Bhatt <bbhatt(a)codeaurora.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam(a)linaro.org>
Reviewed-by: Hemant Kumar <hemantk(a)codeaurora.org>
Link: https://lore.kernel.org/r/1620029090-8975-1-git-send-email-loic.poulain@lin…
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam(a)linaro.org>
---
drivers/bus/mhi/core/pm.c | 18 +++++-------------
1 file changed, 5 insertions(+), 13 deletions(-)
diff --git a/drivers/bus/mhi/core/pm.c b/drivers/bus/mhi/core/pm.c
index e2e59a341fef..704a5e225097 100644
--- a/drivers/bus/mhi/core/pm.c
+++ b/drivers/bus/mhi/core/pm.c
@@ -465,23 +465,15 @@ static void mhi_pm_disable_transition(struct mhi_controller *mhi_cntrl)
/* Trigger MHI RESET so that the device will not access host memory */
if (!MHI_PM_IN_FATAL_STATE(mhi_cntrl->pm_state)) {
- u32 in_reset = -1;
- unsigned long timeout = msecs_to_jiffies(mhi_cntrl->timeout_ms);
-
dev_dbg(dev, "Triggering MHI Reset in device\n");
mhi_set_mhi_state(mhi_cntrl, MHI_STATE_RESET);
/* Wait for the reset bit to be cleared by the device */
- ret = wait_event_timeout(mhi_cntrl->state_event,
- mhi_read_reg_field(mhi_cntrl,
- mhi_cntrl->regs,
- MHICTRL,
- MHICTRL_RESET_MASK,
- MHICTRL_RESET_SHIFT,
- &in_reset) ||
- !in_reset, timeout);
- if (!ret || in_reset)
- dev_err(dev, "Device failed to exit MHI Reset state\n");
+ ret = mhi_poll_reg_field(mhi_cntrl, mhi_cntrl->regs, MHICTRL,
+ MHICTRL_RESET_MASK, MHICTRL_RESET_SHIFT, 0,
+ 25000);
+ if (ret)
+ dev_err(dev, "Device failed to clear MHI Reset\n");
/*
* Device will clear BHI_INTVEC as a part of RESET processing,
--
2.25.1
When reading the base address of the a REDIST region
through KVM_VGIC_V3_ADDR_TYPE_REDIST we expect the
redistributor region list to be populated with a single
element.
However list_first_entry() expects the list to be non empty.
Instead we should use list_first_entry_or_null which effectively
returns NULL if the list is empty.
Fixes: dbd9733ab674 ("KVM: arm/arm64: Replace the single rdist region by a list")
Cc: <Stable(a)vger.kernel.org> # v5.4
Signed-off-by: Eric Auger <eric.auger(a)redhat.com>
Reported-by: Gavin Shan <gshan(a)redhat.com>
Signed-off-by: Marc Zyngier <maz(a)kernel.org>
Link: https://lore.kernel.org/r/20210412150034.29185-1-eric.auger@redhat.com
---
virt/kvm/arm/vgic/vgic-kvm-device.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/virt/kvm/arm/vgic/vgic-kvm-device.c b/virt/kvm/arm/vgic/vgic-kvm-device.c
index 44419679f91a..5eaede3e3b5a 100644
--- a/virt/kvm/arm/vgic/vgic-kvm-device.c
+++ b/virt/kvm/arm/vgic/vgic-kvm-device.c
@@ -87,8 +87,8 @@ int kvm_vgic_addr(struct kvm *kvm, unsigned long type, u64 *addr, bool write)
r = vgic_v3_set_redist_base(kvm, 0, *addr, 0);
goto out;
}
- rdreg = list_first_entry(&vgic->rd_regions,
- struct vgic_redist_region, list);
+ rdreg = list_first_entry_or_null(&vgic->rd_regions,
+ struct vgic_redist_region, list);
if (!rdreg)
addr_ptr = &undef_value;
else
--
2.26.3
The patch below does not apply to the 4.9-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>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 85550c83da421fb12dc1816c45012e1e638d2b38 Mon Sep 17 00:00:00 2001
From: "Steven Rostedt (VMware)" <rostedt(a)goodmis.org>
Date: Thu, 17 Jun 2021 13:47:25 -0400
Subject: [PATCH] tracing: Do not stop recording cmdlines when tracing is off
The saved_cmdlines is used to map pids to the task name, such that the
output of the tracing does not just show pids, but also gives a human
readable name for the task.
If the name is not mapped, the output looks like this:
<...>-1316 [005] ...2 132.044039: ...
Instead of this:
gnome-shell-1316 [005] ...2 132.044039: ...
The names are updated when tracing is running, but are skipped if tracing
is stopped. Unfortunately, this stops the recording of the names if the
top level tracer is stopped, and not if there's other tracers active.
The recording of a name only happens when a new event is written into a
ring buffer, so there is no need to test if tracing is on or not. If
tracing is off, then no event is written and no need to test if tracing is
off or not.
Remove the check, as it hides the names of tasks for events in the
instance buffers.
Cc: stable(a)vger.kernel.org
Fixes: 7ffbd48d5cab2 ("tracing: Cache comms only after an event occurred")
Signed-off-by: Steven Rostedt (VMware) <rostedt(a)goodmis.org>
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 9299057feb56..e220b37e29c6 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -2486,8 +2486,6 @@ static bool tracing_record_taskinfo_skip(int flags)
{
if (unlikely(!(flags & (TRACE_RECORD_CMDLINE | TRACE_RECORD_TGID))))
return true;
- if (atomic_read(&trace_record_taskinfo_disabled) || !tracing_is_on())
- return true;
if (!__this_cpu_read(trace_taskinfo_save))
return true;
return false;
The patch below does not apply to the 4.9-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>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 4fdd595e4f9a1ff6d93ec702eaecae451cfc6591 Mon Sep 17 00:00:00 2001
From: "Steven Rostedt (VMware)" <rostedt(a)goodmis.org>
Date: Thu, 17 Jun 2021 14:32:34 -0400
Subject: [PATCH] tracing: Do not stop recording comms if the trace file is
being read
A while ago, when the "trace" file was opened, tracing was stopped, and
code was added to stop recording the comms to saved_cmdlines, for mapping
of the pids to the task name.
Code has been added that only records the comm if a trace event occurred,
and there's no reason to not trace it if the trace file is opened.
Cc: stable(a)vger.kernel.org
Fixes: 7ffbd48d5cab2 ("tracing: Cache comms only after an event occurred")
Signed-off-by: Steven Rostedt (VMware) <rostedt(a)goodmis.org>
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index e220b37e29c6..d23a09d3eb37 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -2198,9 +2198,6 @@ struct saved_cmdlines_buffer {
};
static struct saved_cmdlines_buffer *savedcmd;
-/* temporary disable recording */
-static atomic_t trace_record_taskinfo_disabled __read_mostly;
-
static inline char *get_saved_cmdlines(int idx)
{
return &savedcmd->saved_cmdlines[idx * TASK_COMM_LEN];
@@ -3996,9 +3993,6 @@ static void *s_start(struct seq_file *m, loff_t *pos)
return ERR_PTR(-EBUSY);
#endif
- if (!iter->snapshot)
- atomic_inc(&trace_record_taskinfo_disabled);
-
if (*pos != iter->pos) {
iter->ent = NULL;
iter->cpu = 0;
@@ -4041,9 +4035,6 @@ static void s_stop(struct seq_file *m, void *p)
return;
#endif
- if (!iter->snapshot)
- atomic_dec(&trace_record_taskinfo_disabled);
-
trace_access_unlock(iter->cpu_file);
trace_event_read_unlock();
}
The patch below does not apply to the 4.14-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>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 8d396bb0a5b62b326f6be7594d8bd46b088296bd Mon Sep 17 00:00:00 2001
From: Jack Pham <jackp(a)codeaurora.org>
Date: Sat, 29 May 2021 12:29:32 -0700
Subject: [PATCH] usb: dwc3: debugfs: Add and remove endpoint dirs dynamically
The DWC3 DebugFS directory and files are currently created once
during probe. This includes creation of subdirectories for each
of the gadget's endpoints. This works fine for peripheral-only
controllers, as dwc3_core_init_mode() calls dwc3_gadget_init()
just prior to calling dwc3_debugfs_init().
However, for dual-role controllers, dwc3_core_init_mode() will
instead call dwc3_drd_init() which is problematic in a few ways.
First, the initial state must be determined, then dwc3_set_mode()
will have to schedule drd_work and by then dwc3_debugfs_init()
could have already been invoked. Even if the initial mode is
peripheral, dwc3_gadget_init() happens after the DebugFS files
are created, and worse so if the initial state is host and the
controller switches to peripheral much later. And secondly,
even if the gadget endpoints' debug entries were successfully
created, if the controller exits peripheral mode, its dwc3_eps
are freed so the debug files would now hold stale references.
So it is best if the DebugFS endpoint entries are created and
removed dynamically at the same time the underlying dwc3_eps are.
Do this by calling dwc3_debugfs_create_endpoint_dir() as each
endpoint is created, and conversely remove the DebugFS entry when
the endpoint is freed.
Fixes: 41ce1456e1db ("usb: dwc3: core: make dwc3_set_mode() work properly")
Cc: stable <stable(a)vger.kernel.org>
Reviewed-by: Peter Chen <peter.chen(a)kernel.org>
Signed-off-by: Jack Pham <jackp(a)codeaurora.org>
Link: https://lore.kernel.org/r/20210529192932.22912-1-jackp@codeaurora.org
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
diff --git a/drivers/usb/dwc3/debug.h b/drivers/usb/dwc3/debug.h
index d0ac89c5b317..d223c54115f4 100644
--- a/drivers/usb/dwc3/debug.h
+++ b/drivers/usb/dwc3/debug.h
@@ -413,9 +413,12 @@ static inline const char *dwc3_gadget_generic_cmd_status_string(int status)
#ifdef CONFIG_DEBUG_FS
+extern void dwc3_debugfs_create_endpoint_dir(struct dwc3_ep *dep);
extern void dwc3_debugfs_init(struct dwc3 *d);
extern void dwc3_debugfs_exit(struct dwc3 *d);
#else
+static inline void dwc3_debugfs_create_endpoint_dir(struct dwc3_ep *dep)
+{ }
static inline void dwc3_debugfs_init(struct dwc3 *d)
{ }
static inline void dwc3_debugfs_exit(struct dwc3 *d)
diff --git a/drivers/usb/dwc3/debugfs.c b/drivers/usb/dwc3/debugfs.c
index 7146ee2ac057..5dbbe53269d3 100644
--- a/drivers/usb/dwc3/debugfs.c
+++ b/drivers/usb/dwc3/debugfs.c
@@ -886,30 +886,14 @@ static void dwc3_debugfs_create_endpoint_files(struct dwc3_ep *dep,
}
}
-static void dwc3_debugfs_create_endpoint_dir(struct dwc3_ep *dep,
- struct dentry *parent)
+void dwc3_debugfs_create_endpoint_dir(struct dwc3_ep *dep)
{
struct dentry *dir;
- dir = debugfs_create_dir(dep->name, parent);
+ dir = debugfs_create_dir(dep->name, dep->dwc->root);
dwc3_debugfs_create_endpoint_files(dep, dir);
}
-static void dwc3_debugfs_create_endpoint_dirs(struct dwc3 *dwc,
- struct dentry *parent)
-{
- int i;
-
- for (i = 0; i < dwc->num_eps; i++) {
- struct dwc3_ep *dep = dwc->eps[i];
-
- if (!dep)
- continue;
-
- dwc3_debugfs_create_endpoint_dir(dep, parent);
- }
-}
-
void dwc3_debugfs_init(struct dwc3 *dwc)
{
struct dentry *root;
@@ -940,7 +924,6 @@ void dwc3_debugfs_init(struct dwc3 *dwc)
&dwc3_testmode_fops);
debugfs_create_file("link_state", 0644, root, dwc,
&dwc3_link_state_fops);
- dwc3_debugfs_create_endpoint_dirs(dwc, root);
}
}
diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 88270eee8a48..f14c2aa83759 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -2753,6 +2753,8 @@ static int dwc3_gadget_init_endpoint(struct dwc3 *dwc, u8 epnum)
INIT_LIST_HEAD(&dep->started_list);
INIT_LIST_HEAD(&dep->cancelled_list);
+ dwc3_debugfs_create_endpoint_dir(dep);
+
return 0;
}
@@ -2796,6 +2798,7 @@ static void dwc3_gadget_free_endpoints(struct dwc3 *dwc)
list_del(&dep->endpoint.ep_list);
}
+ debugfs_remove_recursive(debugfs_lookup(dep->name, dwc->root));
kfree(dep);
}
}