linux-kernel - Re: [PATCH RESEND] drm/amd/pm/powerplay/smumgr/fiji_smumgr: Fix wrong return value of fiji_populate_smc_boot

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Message-ID: <CADnq5_N_-0cd69Zh3zJ0k6xEVs5N7XoJQjdZp+v_kUvqHoTVRA@mail.gmail.com>
Date: Mon, 14 Apr 2025 09:29:12 -0400
From: Alex Deucher <alexdeucher@...il.com>
To: Wentao Liang <vulab@...as.ac.cn>
Cc: kenneth.feng@....com, alexander.deucher@....com, christian.koenig@....com, 
	Xinhui.Pan@....com, airlied@...il.com, simona@...ll.ch, 
	amd-gfx@...ts.freedesktop.org, dri-devel@...ts.freedesktop.org, 
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH RESEND] drm/amd/pm/powerplay/smumgr/fiji_smumgr: Fix wrong
 return value of fiji_populate_smc_boot_level()

On Mon, Apr 14, 2025 at 3:24 AM Wentao Liang <vulab@...as.ac.cn> wrote:
>
> The return value of fiji_populate_smc_boot_level() is always 0, which
> represent the failure of the function. The result of phm_find_boot_level()
> should be recored and return. An error handling is also needed to
> phm_find_boot_level() to reset the boot level when the function fails.
> A proper implementation can be found in tonga_populate_smc_boot_level().
>
> Fixes: dcaf3483ae46 ("drm/amd/pm/powerplay/smumgr/fiji_smumgr: Remove unused variable 'result'")
> Signed-off-by: Wentao Liang <vulab@...as.ac.cn>
> ---
>  .../drm/amd/pm/powerplay/smumgr/fiji_smumgr.c | 23 +++++++++++++------
>  1 file changed, 16 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/pm/powerplay/smumgr/fiji_smumgr.c b/drivers/gpu/drm/amd/pm/powerplay/smumgr/fiji_smumgr.c
> index 5e43ad2b2956..7d0cb3741b94 100644
> --- a/drivers/gpu/drm/amd/pm/powerplay/smumgr/fiji_smumgr.c
> +++ b/drivers/gpu/drm/amd/pm/powerplay/smumgr/fiji_smumgr.c
> @@ -1600,19 +1600,28 @@ static int fiji_populate_smc_uvd_level(struct pp_hwmgr *hwmgr,
>  static int fiji_populate_smc_boot_level(struct pp_hwmgr *hwmgr,
>                 struct SMU73_Discrete_DpmTable *table)
>  {
> +       int result = 0;
>         struct smu7_hwmgr *data = (struct smu7_hwmgr *)(hwmgr->backend);
>
>         table->GraphicsBootLevel = 0;
>         table->MemoryBootLevel = 0;
>
>         /* find boot level from dpm table */
> -       phm_find_boot_level(&(data->dpm_table.sclk_table),
> -                           data->vbios_boot_state.sclk_bootup_value,
> -                           (uint32_t *)&(table->GraphicsBootLevel));
> +       result = phm_find_boot_level(&(data->dpm_table.sclk_table),
> +                                    data->vbios_boot_state.sclk_bootup_value,
> +                                    (uint32_t *)&(table->GraphicsBootLevel));
> +       if (result) {
> +               table->GraphicsBootLevel = 0;
> +               return 0;

This will skip setting the voltages later below.

> +       }
>
> -       phm_find_boot_level(&(data->dpm_table.mclk_table),
> -                           data->vbios_boot_state.mclk_bootup_value,
> -                           (uint32_t *)&(table->MemoryBootLevel));
> +       result = phm_find_boot_level(&(data->dpm_table.mclk_table),
> +                                    data->vbios_boot_state.mclk_bootup_value,
> +                                    (uint32_t *)&(table->MemoryBootLevel));
> +       if (result) {
> +               table->MemoryBootLevel = 0;
> +               return 0;

Same here.

If you are intending to match the logic in
tonga_populate_smc_boot_level(), the existing code already does that
(minus the error message).  This change would break that.  Returning
early may break working devices.

Alex

> +       }
>
>         table->BootVddc  = data->vbios_boot_state.vddc_bootup_value *
>                         VOLTAGE_SCALE;
> @@ -1625,7 +1634,7 @@ static int fiji_populate_smc_boot_level(struct pp_hwmgr *hwmgr,
>         CONVERT_FROM_HOST_TO_SMC_US(table->BootVddci);
>         CONVERT_FROM_HOST_TO_SMC_US(table->BootMVdd);
>
> -       return 0;
> +       return result;
>  }
>
>  static int fiji_populate_smc_initailial_state(struct pp_hwmgr *hwmgr)
> --
> 2.42.0.windows.2
>