Hi Avri,
On Fri, Jan 24, 2025 at 8:36 AM Avri Altman <avri.altman@xxxxxxx> 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@xxxxxxxxxx>
> Signed-off-by: Avri Altman <avri.altman@xxxxxxx>
> --- 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@xxxxxxxxxxxxxx
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
