[PATCH 3/4] drm/amdgpu: Add kernel parameter for ignoring bad page threshold

[Christian König]

Am 19.10.21 um 19:50 schrieb Kent Russell:
> When a GPU hits the bad_page_threshold, it will not be initialized by
> the amdgpu driver. This means that the table cannot be cleared, nor can
> information gathering be performed (getting serial number, BDF, etc).
> Add an override called ignore_bad_page_threshold that can be set to true
> to still initialize the GPU, even when the bad page threshold has been
> reached.

I would rather question the practice of this bad pages threshold.

As far as I know the hardware works perfectly fine even when we have 
more bad badles then expected, we should just warn really loudly about it.

Christian.

>
> Cc: Luben Tuikov <luben.tuikov at amd.com>
> Cc: Mukul Joshi <Mukul.Joshi at amd.com>
> Signed-off-by: Kent Russell <kent.russell at amd.com>
> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu.h     |  1 +
>   drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c | 13 +++++++++++++
>   2 files changed, 14 insertions(+)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> index d58e37fd01f4..b85b67a88a3d 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> @@ -205,6 +205,7 @@ extern struct amdgpu_mgpu_info mgpu_info;
>   extern int amdgpu_ras_enable;
>   extern uint amdgpu_ras_mask;
>   extern int amdgpu_bad_page_threshold;
> +extern bool amdgpu_ignore_bad_page_threshold;
>   extern struct amdgpu_watchdog_timer amdgpu_watchdog_timer;
>   extern int amdgpu_async_gfx_ring;
>   extern int amdgpu_mcbp;
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
> index 96bd63aeeddd..3e9a7b072888 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
> @@ -189,6 +189,7 @@ struct amdgpu_mgpu_info mgpu_info = {
>   int amdgpu_ras_enable = -1;
>   uint amdgpu_ras_mask = 0xffffffff;
>   int amdgpu_bad_page_threshold = -1;
> +bool amdgpu_ignore_bad_page_threshold;
>   struct amdgpu_watchdog_timer amdgpu_watchdog_timer = {
>   	.timeout_fatal_disable = false,
>   	.period = 0x0, /* default to 0x0 (timeout disable) */
> @@ -880,6 +881,18 @@ module_param_named(reset_method, amdgpu_reset_method, int, 0444);
>   MODULE_PARM_DESC(bad_page_threshold, "Bad page threshold(-1 = auto(default value), 0 = disable bad page retirement)");
>   module_param_named(bad_page_threshold, amdgpu_bad_page_threshold, int, 0444);
>   
> +/**
> + * DOC: ignore_bad_page_threshold (bool) Bad page threshold specifies
> + * the threshold value of faulty pages detected by RAS ECC. Once the
> + * threshold is hit, the GPU will not be initialized. Use this parameter
> + * to ignore the bad page threshold so that information gathering can
> + * still be performed. This also allows for booting the GPU to clear
> + * the RAS EEPROM table.
> + */
> +
> +MODULE_PARM_DESC(ignore_bad_page_threshold, "Ignore bad page threshold (false = respect bad page threshold (default value)");
> +module_param_named(ignore_bad_page_threshold, amdgpu_ignore_bad_page_threshold, bool, 0644);
> +
>   MODULE_PARM_DESC(num_kcq, "number of kernel compute queue user want to setup (8 if set to greater than 8 or less than 0, only affect gfx 8+)");
>   module_param_named(num_kcq, amdgpu_num_kcq, int, 0444);
>