drivers/ufs/core/ufshcd.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-)
This commit addresses a lockdep warning triggered by the use of the
clk_gating.lock before it is properly initialized. The warning is as
follows:
[ 4.388838] INFO: trying to register non-static key.
[ 4.395673] The code is fine but needs lockdep annotation, or maybe
[ 4.402118] you didn't initialize this object before use?
[ 4.407673] turning off the locking correctness validator.
[ 4.413334] CPU: 5 UID: 0 PID: 58 Comm: kworker/u32:1 Not tainted 6.12-rc1 #185
[ 4.413343] Hardware name: Qualcomm Technologies, Inc. Robotics RB5 (DT)
[ 4.413362] Call trace:
[ 4.413364] show_stack+0x18/0x24 (C)
[ 4.413374] dump_stack_lvl+0x90/0xd0
[ 4.413384] dump_stack+0x18/0x24
[ 4.413392] register_lock_class+0x498/0x4a8
[ 4.413400] __lock_acquire+0xb4/0x1b90
[ 4.413406] lock_acquire+0x114/0x310
[ 4.413413] _raw_spin_lock_irqsave+0x60/0x88
[ 4.413423] ufshcd_setup_clocks+0x2c0/0x490
[ 4.413433] ufshcd_init+0x198/0x10ec
[ 4.413437] ufshcd_pltfrm_init+0x600/0x7c0
[ 4.413444] ufs_qcom_probe+0x20/0x58
[ 4.413449] platform_probe+0x68/0xd8
[ 4.413459] really_probe+0xbc/0x268
[ 4.413466] __driver_probe_device+0x78/0x12c
[ 4.413473] driver_probe_device+0x40/0x11c
[ 4.413481] __device_attach_driver+0xb8/0xf8
[ 4.413489] bus_for_each_drv+0x84/0xe4
[ 4.413495] __device_attach+0xfc/0x18c
[ 4.413502] device_initial_probe+0x14/0x20
[ 4.413510] bus_probe_device+0xb0/0xb4
[ 4.413517] deferred_probe_work_func+0x8c/0xc8
[ 4.413524] process_scheduled_works+0x250/0x658
[ 4.413534] worker_thread+0x15c/0x2c8
[ 4.413542] kthread+0x134/0x200
[ 4.413550] ret_from_fork+0x10/0x20
To fix this issue, ensure that the spinlock is only used after it
has been properly initialized before using it in `ufshcd_setup_clocks`.
Fixes: 209f4e43b806 ("scsi: ufs: core: Introduce a new clock_gating lock")
Reported-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Avri Altman <avri.altman@wdc.com>
---
Changes since v1:
- move the spin_lock_init(&hba->clk_gating.lock) call from
ufshcd_init_clk_gating() just before the ufshcd_hba_init() call in
ufshcd_init() (Bart)
---
drivers/ufs/core/ufshcd.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
index f6c38cf10382..9b17f6e2f807 100644
--- a/drivers/ufs/core/ufshcd.c
+++ b/drivers/ufs/core/ufshcd.c
@@ -2120,8 +2120,6 @@ static void ufshcd_init_clk_gating(struct ufs_hba *hba)
INIT_DELAYED_WORK(&hba->clk_gating.gate_work, ufshcd_gate_work);
INIT_WORK(&hba->clk_gating.ungate_work, ufshcd_ungate_work);
- spin_lock_init(&hba->clk_gating.lock);
-
hba->clk_gating.clk_gating_workq = alloc_ordered_workqueue(
"ufs_clk_gating_%d", WQ_MEM_RECLAIM | WQ_HIGHPRI,
hba->host->host_no);
@@ -10412,6 +10410,13 @@ int ufshcd_init(struct ufs_hba *hba, void __iomem *mmio_base, unsigned int irq)
hba->irq = irq;
hba->vps = &ufs_hba_vps;
+ /*
+ * Initialize clk_gating.lock early since it is being used in
+ * ufshcd_setup_clocks()
+ */
+ if (ufshcd_is_clkgating_allowed(hba))
+ spin_lock_init(&hba->clk_gating.lock);
+
err = ufshcd_hba_init(hba);
if (err)
goto out_error;
--
2.25.1On 1/23/25 11:33 PM, Avri Altman wrote: > + /* > + * Initialize clk_gating.lock early since it is being used in > + * ufshcd_setup_clocks() > + */ > + if (ufshcd_is_clkgating_allowed(hba)) > + spin_lock_init(&hba->clk_gating.lock); Initializing a spinlock is a very fast operation so please do this unconditionally. Thanks, Bart.
Hi Avri,
On Fri, Jan 24, 2025 at 8:36 AM Avri Altman <avri.altman@wdc.com> wrote:
> This commit addresses a lockdep warning triggered by the use of the
> clk_gating.lock before it is properly initialized. The warning is as
> follows:
>
> [ 4.388838] INFO: trying to register non-static key.
> [ 4.395673] The code is fine but needs lockdep annotation, or maybe
> [ 4.402118] you didn't initialize this object before use?
> [ 4.407673] turning off the locking correctness validator.
> [ 4.413334] CPU: 5 UID: 0 PID: 58 Comm: kworker/u32:1 Not tainted 6.12-rc1 #185
> [ 4.413343] Hardware name: Qualcomm Technologies, Inc. Robotics RB5 (DT)
> [ 4.413362] Call trace:
> [ 4.413364] show_stack+0x18/0x24 (C)
> [ 4.413374] dump_stack_lvl+0x90/0xd0
> [ 4.413384] dump_stack+0x18/0x24
> [ 4.413392] register_lock_class+0x498/0x4a8
> [ 4.413400] __lock_acquire+0xb4/0x1b90
> [ 4.413406] lock_acquire+0x114/0x310
> [ 4.413413] _raw_spin_lock_irqsave+0x60/0x88
> [ 4.413423] ufshcd_setup_clocks+0x2c0/0x490
> [ 4.413433] ufshcd_init+0x198/0x10ec
> [ 4.413437] ufshcd_pltfrm_init+0x600/0x7c0
> [ 4.413444] ufs_qcom_probe+0x20/0x58
> [ 4.413449] platform_probe+0x68/0xd8
> [ 4.413459] really_probe+0xbc/0x268
> [ 4.413466] __driver_probe_device+0x78/0x12c
> [ 4.413473] driver_probe_device+0x40/0x11c
> [ 4.413481] __device_attach_driver+0xb8/0xf8
> [ 4.413489] bus_for_each_drv+0x84/0xe4
> [ 4.413495] __device_attach+0xfc/0x18c
> [ 4.413502] device_initial_probe+0x14/0x20
> [ 4.413510] bus_probe_device+0xb0/0xb4
> [ 4.413517] deferred_probe_work_func+0x8c/0xc8
> [ 4.413524] process_scheduled_works+0x250/0x658
> [ 4.413534] worker_thread+0x15c/0x2c8
> [ 4.413542] kthread+0x134/0x200
> [ 4.413550] ret_from_fork+0x10/0x20
>
> To fix this issue, ensure that the spinlock is only used after it
> has been properly initialized before using it in `ufshcd_setup_clocks`.
>
> Fixes: 209f4e43b806 ("scsi: ufs: core: Introduce a new clock_gating lock")
> Reported-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
> Signed-off-by: Avri Altman <avri.altman@wdc.com>
> --- a/drivers/ufs/core/ufshcd.c
> +++ b/drivers/ufs/core/ufshcd.c
> @@ -10412,6 +10410,13 @@ int ufshcd_init(struct ufs_hba *hba, void __iomem *mmio_base, unsigned int irq)
> hba->irq = irq;
> hba->vps = &ufs_hba_vps;
>
> + /*
> + * Initialize clk_gating.lock early since it is being used in
> + * ufshcd_setup_clocks()
> + */
> + if (ufshcd_is_clkgating_allowed(hba))
This checks if the UFSHCD_CAP_CLK_GATING flag is set, which is only
done in a subset of the host drivers:
drivers/ufs/host/ufs-exynos.c: hba->caps |= UFSHCD_CAP_CLK_GATING |
UFSHCD_CAP_HIBERN8_WITH_CLK_GATING;
drivers/ufs/host/ufs-mediatek.c: hba->caps |= UFSHCD_CAP_CLK_GATING;
drivers/ufs/host/ufs-qcom.c: hba->caps |= UFSHCD_CAP_CLK_GATING |
UFSHCD_CAP_HIBERN8_WITH_CLK_GATING;
drivers/ufs/host/ufs-sprd.c: hba->caps |= UFSHCD_CAP_CLK_GATING |
> + spin_lock_init(&hba->clk_gating.lock);
Hence the spinlock is not uninitialized on all other host drivers.
> +
> err = ufshcd_hba_init(hba);
> if (err)
> goto out_error;
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
Hi Avri,
On Fri, Jan 24, 2025 at 8:36 AM Avri Altman <avri.altman@wdc.com> wrote:
> This commit addresses a lockdep warning triggered by the use of the
> clk_gating.lock before it is properly initialized. The warning is as
> follows:
>
> [ 4.388838] INFO: trying to register non-static key.
> [ 4.395673] The code is fine but needs lockdep annotation, or maybe
> [ 4.402118] you didn't initialize this object before use?
> [ 4.407673] turning off the locking correctness validator.
> [ 4.413334] CPU: 5 UID: 0 PID: 58 Comm: kworker/u32:1 Not tainted 6.12-rc1 #185
> [ 4.413343] Hardware name: Qualcomm Technologies, Inc. Robotics RB5 (DT)
> [ 4.413362] Call trace:
> [ 4.413364] show_stack+0x18/0x24 (C)
> [ 4.413374] dump_stack_lvl+0x90/0xd0
> [ 4.413384] dump_stack+0x18/0x24
> [ 4.413392] register_lock_class+0x498/0x4a8
> [ 4.413400] __lock_acquire+0xb4/0x1b90
> [ 4.413406] lock_acquire+0x114/0x310
> [ 4.413413] _raw_spin_lock_irqsave+0x60/0x88
> [ 4.413423] ufshcd_setup_clocks+0x2c0/0x490
> [ 4.413433] ufshcd_init+0x198/0x10ec
> [ 4.413437] ufshcd_pltfrm_init+0x600/0x7c0
> [ 4.413444] ufs_qcom_probe+0x20/0x58
> [ 4.413449] platform_probe+0x68/0xd8
> [ 4.413459] really_probe+0xbc/0x268
> [ 4.413466] __driver_probe_device+0x78/0x12c
> [ 4.413473] driver_probe_device+0x40/0x11c
> [ 4.413481] __device_attach_driver+0xb8/0xf8
> [ 4.413489] bus_for_each_drv+0x84/0xe4
> [ 4.413495] __device_attach+0xfc/0x18c
> [ 4.413502] device_initial_probe+0x14/0x20
> [ 4.413510] bus_probe_device+0xb0/0xb4
> [ 4.413517] deferred_probe_work_func+0x8c/0xc8
> [ 4.413524] process_scheduled_works+0x250/0x658
> [ 4.413534] worker_thread+0x15c/0x2c8
> [ 4.413542] kthread+0x134/0x200
> [ 4.413550] ret_from_fork+0x10/0x20
>
> To fix this issue, ensure that the spinlock is only used after it
> has been properly initialized before using it in `ufshcd_setup_clocks`.
>
> Fixes: 209f4e43b806 ("scsi: ufs: core: Introduce a new clock_gating lock")
> Reported-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
> Signed-off-by: Avri Altman <avri.altman@wdc.com>
>
> ---
> Changes since v1:
> - move the spin_lock_init(&hba->clk_gating.lock) call from
> ufshcd_init_clk_gating() just before the ufshcd_hba_init() call in
> ufshcd_init() (Bart)
Thanks for the update!
On Renesas R-Car S4 Starter Kit:
BUG: spinlock bad magic on CPU#6, swapper/0/1
lock: 0xffffff84443014e8, .magic: 00000000, .owner: <none>/-1,
.owner_cpu: 0
CPU: 6 UID: 0 PID: 1 Comm: swapper/0 Not tainted
6.13.0-rcar3-initrd-08318-g75abbef32a94 #896
Hardware name: R-Car S4 Starter Kit board (DT)
Call trace:
show_stack+0x18/0x24 (C)
dump_stack_lvl+0x60/0x80
dump_stack+0x18/0x24
spin_bug+0x7c/0xa0
do_raw_spin_lock+0x34/0xb4
_raw_spin_lock_irqsave+0x1c/0x30
class_spinlock_irqsave_constructor+0x18/0x30
ufshcd_setup_clocks+0x98/0x23c
ufshcd_init+0x288/0xd38
ufshcd_pltfrm_init+0x618/0x738
ufs_renesas_probe+0x18/0x24
platform_probe+0x68/0xb8
really_probe+0x138/0x268
__driver_probe_device+0xf4/0x10c
driver_probe_device+0x3c/0xf8
__driver_attach+0xf0/0x100
bus_for_each_dev+0x84/0xdc
driver_attach+0x24/0x30
bus_add_driver+0xe8/0x1dc
driver_register+0xbc/0xf8
__platform_driver_register+0x24/0x30
ufs_renesas_platform_init+0x1c/0x28
do_one_initcall+0x84/0x1f4
kernel_init_freeable+0x238/0x23c
kernel_init+0x20/0x120
ret_from_fork+0x10/0x20
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
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