[PATCH 3/3] drm/amdgpu/vcn: Add parameter to force (en/dis)abling indirect SRAM mode

[Alex Deucher]

On Mon, Jan 16, 2023 at 4:21 PM Guilherme G. Piccoli
<gpiccoli at igalia.com> wrote:
>
> Currently the FW loading path perform some checks based on IP model
> and in case it is advertised as supported, the VCN indirect SRAM
> mode is used.
>
> Happens that in case there's any issue on FW and this mode ends-up
> not being properly supported, the driver probe fails [0]. Debugging
> this requires driver rebuilding, so to allow fast debug and experiments,
> add a parameter to force setting indirect SRAM mode to true/false from
> the kernel command-line; parameter default is -1, which doesn't change
> the current driver's behavior.

Probably a question for Leo or James, but I was under the impression
non-indirect mode didn't work on production silicon for most chips,
but maybe I'm mis-remembering that.

Alex


>
> [0] Example of this issue, observed on Steam Deck:
>
> [drm] kiq ring mec 2 pipe 1 q 0
> [drm] failed to load ucode VCN0_RAM(0x3A)
> [drm] psp gfx command LOAD_IP_FW(0x6) failed and response status is (0xFFFF0000)
> amdgpu 0000:04:00.0: [drm:amdgpu_ring_test_helper [amdgpu]] *ERROR* ring vcn_dec_0 test failed (-110)
> [drm:amdgpu_device_init.cold [amdgpu]] *ERROR* hw_init of IP block <vcn_v3_0> failed -110
> amdgpu 0000:04:00.0: amdgpu: amdgpu_device_ip_init failed
> amdgpu 0000:04:00.0: amdgpu: Fatal error during GPU init
>
> Cc: James Zhu <James.Zhu at amd.com>
> Cc: Lazar Lijo <Lijo.Lazar at amd.com>
> Cc: Leo Liu <leo.liu at amd.com>
> Cc: Mario Limonciello <mario.limonciello at amd.com>
> Cc: Sonny Jiang <sonny.jiang at amd.com>
> Signed-off-by: Guilherme G. Piccoli <gpiccoli at igalia.com>
> ---
>
>
> This work is based on agd5f/amd-staging-drm-next branch.
> Thanks in advance for reviews/comments!
> Cheers,
>
> Guilherme
>
>
>  drivers/gpu/drm/amd/amdgpu/amdgpu.h     | 1 +
>  drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c | 9 +++++++++
>  drivers/gpu/drm/amd/amdgpu/amdgpu_vcn.c | 3 +++
>  3 files changed, 13 insertions(+)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> index 872450a3a164..5d3c92c94f18 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> @@ -215,6 +215,7 @@ extern int amdgpu_noretry;
>  extern int amdgpu_force_asic_type;
>  extern int amdgpu_smartshift_bias;
>  extern int amdgpu_use_xgmi_p2p;
> +extern int amdgpu_indirect_sram;
>  #ifdef CONFIG_HSA_AMD
>  extern int sched_policy;
>  extern bool debug_evictions;
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
> index 06aba201d4db..c7182c0bc841 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
> @@ -187,6 +187,7 @@ int amdgpu_num_kcq = -1;
>  int amdgpu_smartshift_bias;
>  int amdgpu_use_xgmi_p2p = 1;
>  int amdgpu_vcnfw_log;
> +int amdgpu_indirect_sram = -1;
>
>  static void amdgpu_drv_delayed_reset_work_handler(struct work_struct *work);
>
> @@ -941,6 +942,14 @@ MODULE_PARM_DESC(smu_pptable_id,
>         "specify pptable id to be used (-1 = auto(default) value, 0 = use pptable from vbios, > 0 = soft pptable id)");
>  module_param_named(smu_pptable_id, amdgpu_smu_pptable_id, int, 0444);
>
> +/**
> + * DOC: indirect_sram (int)
> + * Allow users to force using (or not) the VCN indirect SRAM mode in the fw load
> + * code. Default is -1, meaning auto (aka, don't mess with driver's behavior).
> + */
> +MODULE_PARM_DESC(indirect_sram, "Force VCN indirect SRAM (-1 = auto (default), 0 = disabled, 1 = enabled)");
> +module_param_named(indirect_sram, amdgpu_indirect_sram, int, 0444);
> +
>  /* These devices are not supported by amdgpu.
>   * They are supported by the mach64, r128, radeon drivers
>   */
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vcn.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vcn.c
> index 1f880e162d9d..a2290087e01c 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vcn.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vcn.c
> @@ -137,6 +137,9 @@ int amdgpu_vcn_sw_init(struct amdgpu_device *adev)
>                 return -EINVAL;
>         }
>
> +       if (amdgpu_indirect_sram >= 0)
> +               adev->vcn.indirect_sram = (bool)amdgpu_indirect_sram;
> +
>         hdr = (const struct common_firmware_header *)adev->vcn.fw->data;
>         adev->vcn.fw_version = le32_to_cpu(hdr->ucode_version);
>
> --
> 2.39.0
>