The patch below does not apply to the 5.15-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-5.15.y
git checkout FETCH_HEAD
git cherry-pick -x 284fb19a3ffb1083c3ad9c00d29749d09dddb99c
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025101650-unloving-grinning-8caf@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 284fb19a3ffb1083c3ad9c00d29749d09dddb99c Mon Sep 17 00:00:00 2001
From: Devarsh Thakkar <devarsht(a)ti.com>
Date: Fri, 4 Jul 2025 18:29:14 +0530
Subject: [PATCH] phy: cadence: cdns-dphy: Fix PLL lock and O_CMN_READY polling
PLL lockup and O_CMN_READY assertion can only happen after common state
machine gets enabled by programming DPHY_CMN_SSM register, but driver was
polling them before the common state machine was enabled which is
incorrect. This is as per the DPHY initialization sequence as mentioned in
J721E TRM [1] at section "12.7.2.4.1.2.1 Start-up Sequence Timing Diagram".
It shows O_CMN_READY polling at the end after common configuration pin
setup where the common configuration pin setup step enables state machine
as referenced in "Table 12-1533. Common Configuration-Related Setup
mentions state machine"
To fix this :
- Add new function callbacks for polling on PLL lock and O_CMN_READY
assertion.
- As state machine and clocks get enabled in power_on callback only, move
the clock related programming part from configure callback to power_on
callback and poll for the PLL lockup and O_CMN_READY assertion after state
machine gets enabled.
- The configure callback only saves the PLL configuration received from the
client driver which will be applied later on in power_on callback.
- Add checks to ensure configure is called before power_on and state
machine is in disabled state before power_on callback is called.
- Disable state machine in power_off so that client driver can re-configure
the PLL by following up a power_off, configure, power_on sequence.
[1]: https://www.ti.com/lit/zip/spruil1
Cc: stable(a)vger.kernel.org
Fixes: 7a343c8bf4b5 ("phy: Add Cadence D-PHY support")
Signed-off-by: Devarsh Thakkar <devarsht(a)ti.com>
Tested-by: Harikrishna Shenoy <h-shenoy(a)ti.com>
Reviewed-by: Tomi Valkeinen <tomi.valkeinen(a)ideasonboard.com>
Link: https://lore.kernel.org/r/20250704125915.1224738-2-devarsht@ti.com
Signed-off-by: Vinod Koul <vkoul(a)kernel.org>
diff --git a/drivers/phy/cadence/cdns-dphy.c b/drivers/phy/cadence/cdns-dphy.c
index 33a42e72362e..da8de0a9d086 100644
--- a/drivers/phy/cadence/cdns-dphy.c
+++ b/drivers/phy/cadence/cdns-dphy.c
@@ -92,6 +92,8 @@ struct cdns_dphy_ops {
void (*set_pll_cfg)(struct cdns_dphy *dphy,
const struct cdns_dphy_cfg *cfg);
unsigned long (*get_wakeup_time_ns)(struct cdns_dphy *dphy);
+ int (*wait_for_pll_lock)(struct cdns_dphy *dphy);
+ int (*wait_for_cmn_ready)(struct cdns_dphy *dphy);
};
struct cdns_dphy {
@@ -101,6 +103,8 @@ struct cdns_dphy {
struct clk *pll_ref_clk;
const struct cdns_dphy_ops *ops;
struct phy *phy;
+ bool is_configured;
+ bool is_powered;
};
/* Order of bands is important since the index is the band number. */
@@ -186,6 +190,16 @@ static unsigned long cdns_dphy_get_wakeup_time_ns(struct cdns_dphy *dphy)
return dphy->ops->get_wakeup_time_ns(dphy);
}
+static int cdns_dphy_wait_for_pll_lock(struct cdns_dphy *dphy)
+{
+ return dphy->ops->wait_for_pll_lock ? dphy->ops->wait_for_pll_lock(dphy) : 0;
+}
+
+static int cdns_dphy_wait_for_cmn_ready(struct cdns_dphy *dphy)
+{
+ return dphy->ops->wait_for_cmn_ready ? dphy->ops->wait_for_cmn_ready(dphy) : 0;
+}
+
static unsigned long cdns_dphy_ref_get_wakeup_time_ns(struct cdns_dphy *dphy)
{
/* Default wakeup time is 800 ns (in a simulated environment). */
@@ -227,7 +241,6 @@ static unsigned long cdns_dphy_j721e_get_wakeup_time_ns(struct cdns_dphy *dphy)
static void cdns_dphy_j721e_set_pll_cfg(struct cdns_dphy *dphy,
const struct cdns_dphy_cfg *cfg)
{
- u32 status;
/*
* set the PWM and PLL Byteclk divider settings to recommended values
@@ -244,13 +257,6 @@ static void cdns_dphy_j721e_set_pll_cfg(struct cdns_dphy *dphy,
writel(DPHY_TX_J721E_WIZ_LANE_RSTB,
dphy->regs + DPHY_TX_J721E_WIZ_RST_CTRL);
-
- readl_poll_timeout(dphy->regs + DPHY_TX_J721E_WIZ_PLL_CTRL, status,
- (status & DPHY_TX_WIZ_PLL_LOCK), 0, POLL_TIMEOUT_US);
-
- readl_poll_timeout(dphy->regs + DPHY_TX_J721E_WIZ_STATUS, status,
- (status & DPHY_TX_WIZ_O_CMN_READY), 0,
- POLL_TIMEOUT_US);
}
static void cdns_dphy_j721e_set_psm_div(struct cdns_dphy *dphy, u8 div)
@@ -258,6 +264,23 @@ static void cdns_dphy_j721e_set_psm_div(struct cdns_dphy *dphy, u8 div)
writel(div, dphy->regs + DPHY_TX_J721E_WIZ_PSM_FREQ);
}
+static int cdns_dphy_j721e_wait_for_pll_lock(struct cdns_dphy *dphy)
+{
+ u32 status;
+
+ return readl_poll_timeout(dphy->regs + DPHY_TX_J721E_WIZ_PLL_CTRL, status,
+ status & DPHY_TX_WIZ_PLL_LOCK, 0, POLL_TIMEOUT_US);
+}
+
+static int cdns_dphy_j721e_wait_for_cmn_ready(struct cdns_dphy *dphy)
+{
+ u32 status;
+
+ return readl_poll_timeout(dphy->regs + DPHY_TX_J721E_WIZ_STATUS, status,
+ status & DPHY_TX_WIZ_O_CMN_READY, 0,
+ POLL_TIMEOUT_US);
+}
+
/*
* This is the reference implementation of DPHY hooks. Specific integration of
* this IP may have to re-implement some of them depending on how they decided
@@ -273,6 +296,8 @@ static const struct cdns_dphy_ops j721e_dphy_ops = {
.get_wakeup_time_ns = cdns_dphy_j721e_get_wakeup_time_ns,
.set_pll_cfg = cdns_dphy_j721e_set_pll_cfg,
.set_psm_div = cdns_dphy_j721e_set_psm_div,
+ .wait_for_pll_lock = cdns_dphy_j721e_wait_for_pll_lock,
+ .wait_for_cmn_ready = cdns_dphy_j721e_wait_for_cmn_ready,
};
static int cdns_dphy_config_from_opts(struct phy *phy,
@@ -328,21 +353,36 @@ static int cdns_dphy_validate(struct phy *phy, enum phy_mode mode, int submode,
static int cdns_dphy_configure(struct phy *phy, union phy_configure_opts *opts)
{
struct cdns_dphy *dphy = phy_get_drvdata(phy);
- struct cdns_dphy_cfg cfg = { 0 };
- int ret, band_ctrl;
- unsigned int reg;
+ int ret;
- ret = cdns_dphy_config_from_opts(phy, &opts->mipi_dphy, &cfg);
- if (ret)
- return ret;
+ ret = cdns_dphy_config_from_opts(phy, &opts->mipi_dphy, &dphy->cfg);
+ if (!ret)
+ dphy->is_configured = true;
+
+ return ret;
+}
+
+static int cdns_dphy_power_on(struct phy *phy)
+{
+ struct cdns_dphy *dphy = phy_get_drvdata(phy);
+ int ret;
+ u32 reg;
+
+ if (!dphy->is_configured || dphy->is_powered)
+ return -EINVAL;
+
+ clk_prepare_enable(dphy->psm_clk);
+ clk_prepare_enable(dphy->pll_ref_clk);
/*
* Configure the internal PSM clk divider so that the DPHY has a
* 1MHz clk (or something close).
*/
ret = cdns_dphy_setup_psm(dphy);
- if (ret)
- return ret;
+ if (ret) {
+ dev_err(&dphy->phy->dev, "Failed to setup PSM with error %d\n", ret);
+ goto err_power_on;
+ }
/*
* Configure attach clk lanes to data lanes: the DPHY has 2 clk lanes
@@ -357,40 +397,60 @@ static int cdns_dphy_configure(struct phy *phy, union phy_configure_opts *opts)
* Configure the DPHY PLL that will be used to generate the TX byte
* clk.
*/
- cdns_dphy_set_pll_cfg(dphy, &cfg);
+ cdns_dphy_set_pll_cfg(dphy, &dphy->cfg);
- band_ctrl = cdns_dphy_tx_get_band_ctrl(opts->mipi_dphy.hs_clk_rate);
- if (band_ctrl < 0)
- return band_ctrl;
+ ret = cdns_dphy_tx_get_band_ctrl(dphy->cfg.hs_clk_rate);
+ if (ret < 0) {
+ dev_err(&dphy->phy->dev, "Failed to get band control value with error %d\n", ret);
+ goto err_power_on;
+ }
- reg = FIELD_PREP(DPHY_BAND_CFG_LEFT_BAND, band_ctrl) |
- FIELD_PREP(DPHY_BAND_CFG_RIGHT_BAND, band_ctrl);
+ reg = FIELD_PREP(DPHY_BAND_CFG_LEFT_BAND, ret) |
+ FIELD_PREP(DPHY_BAND_CFG_RIGHT_BAND, ret);
writel(reg, dphy->regs + DPHY_BAND_CFG);
- return 0;
-}
-
-static int cdns_dphy_power_on(struct phy *phy)
-{
- struct cdns_dphy *dphy = phy_get_drvdata(phy);
-
- clk_prepare_enable(dphy->psm_clk);
- clk_prepare_enable(dphy->pll_ref_clk);
-
/* Start TX state machine. */
writel(DPHY_CMN_SSM_EN | DPHY_CMN_TX_MODE_EN,
dphy->regs + DPHY_CMN_SSM);
+ ret = cdns_dphy_wait_for_pll_lock(dphy);
+ if (ret) {
+ dev_err(&dphy->phy->dev, "Failed to lock PLL with error %d\n", ret);
+ goto err_power_on;
+ }
+
+ ret = cdns_dphy_wait_for_cmn_ready(dphy);
+ if (ret) {
+ dev_err(&dphy->phy->dev, "O_CMN_READY signal failed to assert with error %d\n",
+ ret);
+ goto err_power_on;
+ }
+
+ dphy->is_powered = true;
+
return 0;
+
+err_power_on:
+ clk_disable_unprepare(dphy->pll_ref_clk);
+ clk_disable_unprepare(dphy->psm_clk);
+
+ return ret;
}
static int cdns_dphy_power_off(struct phy *phy)
{
struct cdns_dphy *dphy = phy_get_drvdata(phy);
+ u32 reg;
clk_disable_unprepare(dphy->pll_ref_clk);
clk_disable_unprepare(dphy->psm_clk);
+ /* Stop TX state machine. */
+ reg = readl(dphy->regs + DPHY_CMN_SSM);
+ writel(reg & ~DPHY_CMN_SSM_EN, dphy->regs + DPHY_CMN_SSM);
+
+ dphy->is_powered = false;
+
return 0;
}
The patch below does not apply to the 5.15-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-5.15.y
git checkout FETCH_HEAD
git cherry-pick -x 501302d5cee0d8e8ec2c4a5919c37e0df9abc99b
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025101651-unlimited-rippling-daa6@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 501302d5cee0d8e8ec2c4a5919c37e0df9abc99b Mon Sep 17 00:00:00 2001
From: Xiao Liang <shaw.leon(a)gmail.com>
Date: Sun, 17 Aug 2025 00:30:15 +0800
Subject: [PATCH] padata: Reset next CPU when reorder sequence wraps around
When seq_nr wraps around, the next reorder job with seq 0 is hashed to
the first CPU in padata_do_serial(). Correspondingly, need reset pd->cpu
to the first one when pd->processed wraps around. Otherwise, if the
number of used CPUs is not a power of 2, padata_find_next() will be
checking a wrong list, hence deadlock.
Fixes: 6fc4dbcf0276 ("padata: Replace delayed timer with immediate workqueue in padata_reorder")
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Xiao Liang <shaw.leon(a)gmail.com>
Signed-off-by: Herbert Xu <herbert(a)gondor.apana.org.au>
diff --git a/kernel/padata.c b/kernel/padata.c
index f85f8bd788d0..833740d75483 100644
--- a/kernel/padata.c
+++ b/kernel/padata.c
@@ -291,8 +291,12 @@ static void padata_reorder(struct padata_priv *padata)
struct padata_serial_queue *squeue;
int cb_cpu;
- cpu = cpumask_next_wrap(cpu, pd->cpumask.pcpu);
processed++;
+ /* When sequence wraps around, reset to the first CPU. */
+ if (unlikely(processed == 0))
+ cpu = cpumask_first(pd->cpumask.pcpu);
+ else
+ cpu = cpumask_next_wrap(cpu, pd->cpumask.pcpu);
cb_cpu = padata->cb_cpu;
squeue = per_cpu_ptr(pd->squeue, cb_cpu);
The patch below does not apply to the 5.4-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-5.4.y
git checkout FETCH_HEAD
git cherry-pick -x 501302d5cee0d8e8ec2c4a5919c37e0df9abc99b
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025101651-kerosene-quartered-684e@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 501302d5cee0d8e8ec2c4a5919c37e0df9abc99b Mon Sep 17 00:00:00 2001
From: Xiao Liang <shaw.leon(a)gmail.com>
Date: Sun, 17 Aug 2025 00:30:15 +0800
Subject: [PATCH] padata: Reset next CPU when reorder sequence wraps around
When seq_nr wraps around, the next reorder job with seq 0 is hashed to
the first CPU in padata_do_serial(). Correspondingly, need reset pd->cpu
to the first one when pd->processed wraps around. Otherwise, if the
number of used CPUs is not a power of 2, padata_find_next() will be
checking a wrong list, hence deadlock.
Fixes: 6fc4dbcf0276 ("padata: Replace delayed timer with immediate workqueue in padata_reorder")
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Xiao Liang <shaw.leon(a)gmail.com>
Signed-off-by: Herbert Xu <herbert(a)gondor.apana.org.au>
diff --git a/kernel/padata.c b/kernel/padata.c
index f85f8bd788d0..833740d75483 100644
--- a/kernel/padata.c
+++ b/kernel/padata.c
@@ -291,8 +291,12 @@ static void padata_reorder(struct padata_priv *padata)
struct padata_serial_queue *squeue;
int cb_cpu;
- cpu = cpumask_next_wrap(cpu, pd->cpumask.pcpu);
processed++;
+ /* When sequence wraps around, reset to the first CPU. */
+ if (unlikely(processed == 0))
+ cpu = cpumask_first(pd->cpumask.pcpu);
+ else
+ cpu = cpumask_next_wrap(cpu, pd->cpumask.pcpu);
cb_cpu = padata->cb_cpu;
squeue = per_cpu_ptr(pd->squeue, cb_cpu);
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 501302d5cee0d8e8ec2c4a5919c37e0df9abc99b
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025101651-sizing-subfloor-8c1d@gregkh' --subject-prefix 'PATCH 5.10.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 501302d5cee0d8e8ec2c4a5919c37e0df9abc99b Mon Sep 17 00:00:00 2001
From: Xiao Liang <shaw.leon(a)gmail.com>
Date: Sun, 17 Aug 2025 00:30:15 +0800
Subject: [PATCH] padata: Reset next CPU when reorder sequence wraps around
When seq_nr wraps around, the next reorder job with seq 0 is hashed to
the first CPU in padata_do_serial(). Correspondingly, need reset pd->cpu
to the first one when pd->processed wraps around. Otherwise, if the
number of used CPUs is not a power of 2, padata_find_next() will be
checking a wrong list, hence deadlock.
Fixes: 6fc4dbcf0276 ("padata: Replace delayed timer with immediate workqueue in padata_reorder")
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Xiao Liang <shaw.leon(a)gmail.com>
Signed-off-by: Herbert Xu <herbert(a)gondor.apana.org.au>
diff --git a/kernel/padata.c b/kernel/padata.c
index f85f8bd788d0..833740d75483 100644
--- a/kernel/padata.c
+++ b/kernel/padata.c
@@ -291,8 +291,12 @@ static void padata_reorder(struct padata_priv *padata)
struct padata_serial_queue *squeue;
int cb_cpu;
- cpu = cpumask_next_wrap(cpu, pd->cpumask.pcpu);
processed++;
+ /* When sequence wraps around, reset to the first CPU. */
+ if (unlikely(processed == 0))
+ cpu = cpumask_first(pd->cpumask.pcpu);
+ else
+ cpu = cpumask_next_wrap(cpu, pd->cpumask.pcpu);
cb_cpu = padata->cb_cpu;
squeue = per_cpu_ptr(pd->squeue, cb_cpu);
The patch below does not apply to the 6.1-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-6.1.y
git checkout FETCH_HEAD
git cherry-pick -x 501302d5cee0d8e8ec2c4a5919c37e0df9abc99b
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025101650-dreamless-dry-49d5@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 501302d5cee0d8e8ec2c4a5919c37e0df9abc99b Mon Sep 17 00:00:00 2001
From: Xiao Liang <shaw.leon(a)gmail.com>
Date: Sun, 17 Aug 2025 00:30:15 +0800
Subject: [PATCH] padata: Reset next CPU when reorder sequence wraps around
When seq_nr wraps around, the next reorder job with seq 0 is hashed to
the first CPU in padata_do_serial(). Correspondingly, need reset pd->cpu
to the first one when pd->processed wraps around. Otherwise, if the
number of used CPUs is not a power of 2, padata_find_next() will be
checking a wrong list, hence deadlock.
Fixes: 6fc4dbcf0276 ("padata: Replace delayed timer with immediate workqueue in padata_reorder")
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Xiao Liang <shaw.leon(a)gmail.com>
Signed-off-by: Herbert Xu <herbert(a)gondor.apana.org.au>
diff --git a/kernel/padata.c b/kernel/padata.c
index f85f8bd788d0..833740d75483 100644
--- a/kernel/padata.c
+++ b/kernel/padata.c
@@ -291,8 +291,12 @@ static void padata_reorder(struct padata_priv *padata)
struct padata_serial_queue *squeue;
int cb_cpu;
- cpu = cpumask_next_wrap(cpu, pd->cpumask.pcpu);
processed++;
+ /* When sequence wraps around, reset to the first CPU. */
+ if (unlikely(processed == 0))
+ cpu = cpumask_first(pd->cpumask.pcpu);
+ else
+ cpu = cpumask_next_wrap(cpu, pd->cpumask.pcpu);
cb_cpu = padata->cb_cpu;
squeue = per_cpu_ptr(pd->squeue, cb_cpu);
The patch below does not apply to the 6.6-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-6.6.y
git checkout FETCH_HEAD
git cherry-pick -x 501302d5cee0d8e8ec2c4a5919c37e0df9abc99b
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025101650-feline-ellipse-6256@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 501302d5cee0d8e8ec2c4a5919c37e0df9abc99b Mon Sep 17 00:00:00 2001
From: Xiao Liang <shaw.leon(a)gmail.com>
Date: Sun, 17 Aug 2025 00:30:15 +0800
Subject: [PATCH] padata: Reset next CPU when reorder sequence wraps around
When seq_nr wraps around, the next reorder job with seq 0 is hashed to
the first CPU in padata_do_serial(). Correspondingly, need reset pd->cpu
to the first one when pd->processed wraps around. Otherwise, if the
number of used CPUs is not a power of 2, padata_find_next() will be
checking a wrong list, hence deadlock.
Fixes: 6fc4dbcf0276 ("padata: Replace delayed timer with immediate workqueue in padata_reorder")
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Xiao Liang <shaw.leon(a)gmail.com>
Signed-off-by: Herbert Xu <herbert(a)gondor.apana.org.au>
diff --git a/kernel/padata.c b/kernel/padata.c
index f85f8bd788d0..833740d75483 100644
--- a/kernel/padata.c
+++ b/kernel/padata.c
@@ -291,8 +291,12 @@ static void padata_reorder(struct padata_priv *padata)
struct padata_serial_queue *squeue;
int cb_cpu;
- cpu = cpumask_next_wrap(cpu, pd->cpumask.pcpu);
processed++;
+ /* When sequence wraps around, reset to the first CPU. */
+ if (unlikely(processed == 0))
+ cpu = cpumask_first(pd->cpumask.pcpu);
+ else
+ cpu = cpumask_next_wrap(cpu, pd->cpumask.pcpu);
cb_cpu = padata->cb_cpu;
squeue = per_cpu_ptr(pd->squeue, cb_cpu);
The patch below does not apply to the 6.12-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-6.12.y
git checkout FETCH_HEAD
git cherry-pick -x 501302d5cee0d8e8ec2c4a5919c37e0df9abc99b
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025101649-sector-ruined-1f7a@gregkh' --subject-prefix 'PATCH 6.12.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 501302d5cee0d8e8ec2c4a5919c37e0df9abc99b Mon Sep 17 00:00:00 2001
From: Xiao Liang <shaw.leon(a)gmail.com>
Date: Sun, 17 Aug 2025 00:30:15 +0800
Subject: [PATCH] padata: Reset next CPU when reorder sequence wraps around
When seq_nr wraps around, the next reorder job with seq 0 is hashed to
the first CPU in padata_do_serial(). Correspondingly, need reset pd->cpu
to the first one when pd->processed wraps around. Otherwise, if the
number of used CPUs is not a power of 2, padata_find_next() will be
checking a wrong list, hence deadlock.
Fixes: 6fc4dbcf0276 ("padata: Replace delayed timer with immediate workqueue in padata_reorder")
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Xiao Liang <shaw.leon(a)gmail.com>
Signed-off-by: Herbert Xu <herbert(a)gondor.apana.org.au>
diff --git a/kernel/padata.c b/kernel/padata.c
index f85f8bd788d0..833740d75483 100644
--- a/kernel/padata.c
+++ b/kernel/padata.c
@@ -291,8 +291,12 @@ static void padata_reorder(struct padata_priv *padata)
struct padata_serial_queue *squeue;
int cb_cpu;
- cpu = cpumask_next_wrap(cpu, pd->cpumask.pcpu);
processed++;
+ /* When sequence wraps around, reset to the first CPU. */
+ if (unlikely(processed == 0))
+ cpu = cpumask_first(pd->cpumask.pcpu);
+ else
+ cpu = cpumask_next_wrap(cpu, pd->cpumask.pcpu);
cb_cpu = padata->cb_cpu;
squeue = per_cpu_ptr(pd->squeue, cb_cpu);