RE: [PATCH] drm/amd/ras: eliminate gpu reset lock protection for ras ta runtime command path

AMD General

Hi, @Sun, Ce(Overlord)<mailto:[email protected]>,

Could you add a device lost check to exit early from ras psp command wait and see if that helps?

        while (*((uint64_t *)psp_fence_buf->mem_cpu_addr) !=
                   psp_ctx->in_fence_value) {
                if (--timeout == 0)
                        break;
                /*
                 * Shouldn't wait for timeout when err_event_athub occurs,
                 * because gpu reset thread triggered and lock resource should
                 * be released for psp resume sequence.
                 */
                if (ras_core_ras_interrupt_detected(ras_core))
                        break;

Thanks,
Lijo
From: Sun, Ce(Overlord) <[email protected]>
Sent: Friday, July 24, 2026 7:59 AM
To: Chai, Thomas <[email protected]>; [email protected]
Cc: Zhang, Hawking <[email protected]>; Zhou1, Tao <[email protected]>; Yang, Stanley <[email protected]>; Lazar, Lijo <[email protected]>
Subject: Re: [PATCH] drm/amd/ras: eliminate gpu reset lock protection for ras ta runtime command path

AMD General

Hi Thomas,

Thanks for your comments.We cannot predict when the DPC interrupt will be triggered, so it is impossible to prevent the driver from sending messages to PMFW during DPC interrupt processing - this is exactly the issue we are encountering, which delays DPC recovery and causes functional anomalies. After cross-checking the legacy RAS implementation, GPU reset lock is not required in this code path.
________________________________
From: Chai, Thomas <[email protected]<mailto:[email protected]>>
Sent: Friday, July 24, 2026 9:56 AM
To: Sun, Ce(Overlord) <[email protected]<mailto:[email protected]>>; [email protected]<mailto:[email protected]> <[email protected]<mailto:[email protected]>>
Cc: Zhang, Hawking <[email protected]<mailto:[email protected]>>; Zhou1, Tao <[email protected]<mailto:[email protected]>>; Yang, Stanley <[email protected]<mailto:[email protected]>>; Lazar, Lijo <[email protected]<mailto:[email protected]>>
Subject: RE: [PATCH] drm/amd/ras: eliminate gpu reset lock protection for ras ta runtime command path

AMD General

Cannot send command during GPU reset, which may cause a system exception.

Best Regards,
Thomas
-----Original Message-----
From: Sun, Ce(Overlord) <[email protected]<mailto:[email protected]>>
Sent: Friday, July 24, 2026 7:59 AM
To: [email protected]<mailto:[email protected]>
Cc: Zhang, Hawking <[email protected]<mailto:[email protected]>>; Chai, Thomas <[email protected]<mailto:[email protected]>>; Zhou1, Tao <[email protected]<mailto:[email protected]>>; Yang, Stanley <[email protected]<mailto:[email protected]>>; Lazar, Lijo <[email protected]<mailto:[email protected]>>; Sun, Ce(Overlord) <[email protected]<mailto:[email protected]>>
Subject: [PATCH] drm/amd/ras: eliminate gpu reset lock protection for ras ta runtime command path

When PMFW enters mode-1 state, it will not respond to incoming messages.
Holding gpu reset lock before dispatching messages to PMFW would defer GPU recovery processing, cause undesirable timing skew.

Remove the gpu reset lock acquire and release logic inside send_ras_ta_runtime_cmd, prioritize GPU recovery execution over PMFW message delivery to fix timing dependency problems.

Signed-off-by: Ce Sun <[email protected]<mailto:[email protected]>>
---
 drivers/gpu/drm/amd/ras/rascore/ras_psp.c | 6 ------
 1 file changed, 6 deletions(-)

diff --git a/drivers/gpu/drm/amd/ras/rascore/ras_psp.c b/drivers/gpu/drm/amd/ras/rascore/ras_psp.c
index 358f602b167d..fbe91eb67c0e 100644
--- a/drivers/gpu/drm/amd/ras/rascore/ras_psp.c
+++ b/drivers/gpu/drm/amd/ras/rascore/ras_psp.c
@@ -374,11 +374,6 @@ static int send_ras_ta_runtime_cmd(struct ras_core_context *ras_core,
        if (!cmd_mem)
                return -ENOMEM;

-       if (!ras_core_down_trylock_gpu_reset_lock(ras_core)) {
-               ret = -EACCES;
-               goto out;
-       }
-
        ras_cmd = (struct ras_ta_cmd *)cmd_mem->mem_cpu_addr;

        mutex_lock(&ta_ctx->ta_mutex);
@@ -422,7 +417,6 @@ static int send_ras_ta_runtime_cmd(struct ras_core_context *ras_core,

 unlock:
        mutex_unlock(&ta_ctx->ta_mutex);
-       ras_core_up_gpu_reset_lock(ras_core);
 out:
        ras_psp_put_gpu_mem(ras_core, cmd_mem);
        return ret;
--
2.34.1