[AMD Official Use Only]
> -----Original Message-----
> From: amd-gfx <amd-gfx-bounces@xxxxxxxxxxxxxxxxxxxxx> On Behalf Of Lang
> Yu
> Sent: Thursday, December 9, 2021 4:49 PM
> To: amd-gfx@xxxxxxxxxxxxxxxxxxxxx
> Cc: Grodzovsky, Andrey <Andrey.Grodzovsky@xxxxxxx>; Lazar, Lijo
> <Lijo.Lazar@xxxxxxx>; Huang, Ray <Ray.Huang@xxxxxxx>; Deucher,
> Alexander <Alexander.Deucher@xxxxxxx>; Yu, Lang <Lang.Yu@xxxxxxx>;
> Koenig, Christian <Christian.Koenig@xxxxxxx>
> Subject: [PATCH 2/2] drm/amdgpu: add support for SMU debug option
>
> SMU firmware guys expect the driver maintains error context
> and doesn't interact with SMU any more when SMU errors occurred.
> That will aid in debugging SMU firmware issues.
>
> Add SMU debug option support for this request, it can be
> enabled or disabled via amdgpu_smu_debug debugfs file.
> When enabled, it brings hardware to a kind of halt state
> so that no one can touch it any more in the envent of SMU
> errors.
>
> Currently, dirver interacts with SMU via sending messages.
> And threre are three ways to sending messages to SMU.
> Handle them respectively as following:
>
> 1, smu_cmn_send_smc_msg_with_param() for normal timeout cases
>
> Halt on any error.
>
> 2, smu_cmn_send_msg_without_waiting()/smu_cmn_wait_for_response()
> for longer timeout cases
>
> Halt on errors apart from ETIME. Otherwise this way won't work.
>
> 3, smu_cmn_send_msg_without_waiting() for no waiting cases
>
> Halt on errors apart from ETIME. Otherwise second way won't work.
>
> After halting, use BUG() to explicitly notify users.
>
> == Command Guide ==
>
> 1, enable SMU debug option
>
> # echo 1 > /sys/kernel/debug/dri/0/amdgpu_smu_debug
>
> 2, disable SMU debug option
>
> # echo 0 > /sys/kernel/debug/dri/0/amdgpu_smu_debug
>
> v4:
> - Set to halt state instead of a simple hang.(Christian)
>
> v3:
> - Use debugfs_create_bool().(Christian)
> - Put variable into smu_context struct.
> - Don't resend command when timeout.
>
> v2:
> - Resend command when timeout.(Lijo)
> - Use debugfs file instead of module parameter.
>
> Signed-off-by: Lang Yu <lang.yu@xxxxxxx>
> ---
> drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c | 3 +++
> drivers/gpu/drm/amd/pm/inc/amdgpu_smu.h | 5 +++++
> drivers/gpu/drm/amd/pm/swsmu/smu_cmn.c | 20
> +++++++++++++++++++-
> 3 files changed, 27 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
> b/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
> index 164d6a9e9fbb..86cd888c7822 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
> @@ -1618,6 +1618,9 @@ int amdgpu_debugfs_init(struct amdgpu_device
> *adev)
> if (!debugfs_initialized())
> return 0;
>
> + debugfs_create_bool("amdgpu_smu_debug", 0600, root,
> + &adev->smu.smu_debug_mode);
> +
> ent = debugfs_create_file("amdgpu_preempt_ib", 0600, root, adev,
> &fops_ib_preempt);
> if (IS_ERR(ent)) {
> diff --git a/drivers/gpu/drm/amd/pm/inc/amdgpu_smu.h
> b/drivers/gpu/drm/amd/pm/inc/amdgpu_smu.h
> index f738f7dc20c9..50dbf5594a9d 100644
> --- a/drivers/gpu/drm/amd/pm/inc/amdgpu_smu.h
> +++ b/drivers/gpu/drm/amd/pm/inc/amdgpu_smu.h
> @@ -569,6 +569,11 @@ struct smu_context
> struct smu_user_dpm_profile user_dpm_profile;
>
> struct stb_context stb_context;
> + /*
> + * When enabled, it makes SMU errors fatal.
> + * (0 = disabled (default), 1 = enabled)
> + */
> + bool smu_debug_mode;
[Quan, Evan] Can you expand this to bit mask(as ppfeaturemask)? So that in future we can add support for other debug features.
> };
>
> struct i2c_adapter;
> diff --git a/drivers/gpu/drm/amd/pm/swsmu/smu_cmn.c
> b/drivers/gpu/drm/amd/pm/swsmu/smu_cmn.c
> index 048ca1673863..84016d22c075 100644
> --- a/drivers/gpu/drm/amd/pm/swsmu/smu_cmn.c
> +++ b/drivers/gpu/drm/amd/pm/swsmu/smu_cmn.c
> @@ -272,6 +272,11 @@ int smu_cmn_send_msg_without_waiting(struct
> smu_context *smu,
> __smu_cmn_send_msg(smu, msg_index, param);
> res = 0;
> Out:
> + if (unlikely(smu->smu_debug_mode) && res && (res != -ETIME)) {
> + amdgpu_device_halt(smu->adev);
> + BUG();
[Quan, Evan] I agree amdgpu_device_halt() is a good idea. Christian and Andrey can share you more insights about that.
Do we still need the "BUG()" then?
BR
Evan
> + }
> +
> return res;
> }
>
> @@ -288,9 +293,17 @@ int smu_cmn_send_msg_without_waiting(struct
> smu_context *smu,
> int smu_cmn_wait_for_response(struct smu_context *smu)
> {
> u32 reg;
> + int res;
>
> reg = __smu_cmn_poll_stat(smu);
> - return __smu_cmn_reg2errno(smu, reg);
> + res = __smu_cmn_reg2errno(smu, reg);
> +
> + if (unlikely(smu->smu_debug_mode) && res && (res != -ETIME)) {
> + amdgpu_device_halt(smu->adev);
> + BUG();
> + }
> +
> + return res;
> }
>
> /**
> @@ -357,6 +370,11 @@ int smu_cmn_send_smc_msg_with_param(struct
> smu_context *smu,
> if (read_arg)
> smu_cmn_read_arg(smu, read_arg);
> Out:
> + if (unlikely(smu->smu_debug_mode) && res) {
> + amdgpu_device_halt(smu->adev);
> + BUG();
> + }
> +
> mutex_unlock(&smu->message_lock);
> return res;
> }
> --
> 2.25.1
