linux-kernel - RE: [PATCH v2] drm/amd/pm/powerplay/smumgr/fiji_smumgr: Add error check in fiji_populate_smc_boot

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID:
 <DM4PR12MB5165E65CD092473E3592ED488EBC2@DM4PR12MB5165.namprd12.prod.outlook.com>
Date: Thu, 17 Apr 2025 08:45:45 +0000
From: "Feng, Kenneth" <Kenneth.Feng@....com>
To: Alex Deucher <alexdeucher@...il.com>, Wentao Liang <vulab@...as.ac.cn>
CC: "Deucher, Alexander" <Alexander.Deucher@....com>, "Koenig, Christian"
	<Christian.Koenig@....com>, "Xinhui.Pan@....com" <Xinhui.Pan@....com>,
	"airlied@...il.com" <airlied@...il.com>, "simona@...ll.ch" <simona@...ll.ch>,
	"amd-gfx@...ts.freedesktop.org" <amd-gfx@...ts.freedesktop.org>,
	"dri-devel@...ts.freedesktop.org" <dri-devel@...ts.freedesktop.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	"stable@...r.kernel.org" <stable@...r.kernel.org>
Subject: RE: [PATCH v2] drm/amd/pm/powerplay/smumgr/fiji_smumgr: Add error
 check in fiji_populate_smc_boot_level()

[AMD Official Use Only - AMD Internal Distribution Only]

-----Original Message-----
From: Alex Deucher <alexdeucher@...il.com>
Sent: Thursday, April 17, 2025 7:03 AM
To: Wentao Liang <vulab@...as.ac.cn>
Cc: Feng, Kenneth <Kenneth.Feng@....com>; Deucher, Alexander <Alexander.Deucher@....com>; Koenig, Christian <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; stable@...r.kernel.org
Subject: Re: [PATCH v2] drm/amd/pm/powerplay/smumgr/fiji_smumgr: Add error check in fiji_populate_smc_boot_level()

Caution: This message originated from an External Source. Use proper caution when opening attachments, clicking links, or responding.


On Tue, Apr 15, 2025 at 6:23 AM Wentao Liang <vulab@...as.ac.cn> wrote:
>
> The return value of fiji_populate_smc_boot_level() is needs to be checked.
> 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'")
> Cc: stable@...r.kernel.org # v5.11+

I don't know that this is a fix per se so I don't think stable is appropriate.

This is probably ok, but TBH, I don't really remember how the pptables were set up on these old chips and whether changing the current behavior would actually fix or break anything.  I'd be more inclined to just leave the logic as is lest something break.

In production, VBIOS makes sure that the bootup clock values match the ones in pptable. So the error can't happen in reality. And the result is overridden to 0 anyway, on tonga as well.
Thanks.

Kenneth Feng


> Signed-off-by: Wentao Liang <vulab@...as.ac.cn>
> ---
> v2: Fix error code.
>
>  .../drm/amd/pm/powerplay/smumgr/fiji_smumgr.c | 23
> ++++++++++++++-----
>  1 file changed, 17 insertions(+), 6 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..78ba22f249b2 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 +1600,30 @@ 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 != 0) {
> +               table->GraphicsBootLevel = 0;
> +               pr_err("VBIOS did not find boot engine clock value in dependency table. Using Graphics DPM level 0!\n");
> +               result = 0;
> +       }
>
> -       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 != 0) {
> +               table->MemoryBootLevel = 0;
> +               pr_err("VBIOS did not find boot engine clock value in dependency table. Using Memory DPM level 0!\n");
> +               result = 0;
> +       }
>
>         table->BootVddc  = data->vbios_boot_state.vddc_bootup_value *
>                         VOLTAGE_SCALE;
> --
> 2.42.0.windows.2
>