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author | Darren Powell <darren.powell@amd.com> | 2022-04-05 22:17:08 -0400 |
---|---|---|
committer | Alex Deucher <alexander.deucher@amd.com> | 2022-04-19 13:58:32 -0400 |
commit | f24044bd9b16a059e5773170fbfa1badc536d657 (patch) | |
tree | 1b8ef57a6083f44b43d485dd390a7e5fe3355b9e | |
parent | eea5c7b3390c6e006ba4cbd906447dd8cea8cfbf (diff) | |
download | linux-f24044bd9b16a059e5773170fbfa1badc536d657.tar.bz2 |
amdgpu/pm: Clarify documentation of error handling in send_smc_mesg
Clarify the smu_cmn_send_smc_msg_with_param documentation to mention two
cases exist where messages are silently dropped with no error returned.
These cases occur in unusual situations where either:
1. the message type is not allowed to a virtual GPU, or
2. a PCI recovery is underway and the HW is not yet in sync with the SW
For more details see
commit 4ea5081c82c4 ("drm/amd/powerplay: enable SMC message filter")
commit bf36b52e781d ("drm/amdgpu: Avoid accessing HW when suspending SW state")
(v2)
Reworked with suggestions from Luben & Paul
(v3)
Updated wording as per Luben's feedback
Corrected error stating all messages denied on virtual GPU
(each GPU has mask of which messages are allowed)
Signed-off-by: Darren Powell <darren.powell@amd.com>
Reviewed-by: Luben Tuikov <luben.tuikov@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
-rw-r--r-- | drivers/gpu/drm/amd/pm/swsmu/smu_cmn.c | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/drivers/gpu/drm/amd/pm/swsmu/smu_cmn.c b/drivers/gpu/drm/amd/pm/swsmu/smu_cmn.c index b8d0c70ff668..f12319883a80 100644 --- a/drivers/gpu/drm/amd/pm/swsmu/smu_cmn.c +++ b/drivers/gpu/drm/amd/pm/swsmu/smu_cmn.c @@ -356,9 +356,11 @@ int smu_cmn_wait_for_response(struct smu_context *smu) * completion of the command, and return back a value from the SMU in * @read_arg pointer. * - * Return 0 on success, -errno on error, if we weren't able to send - * the message or if the message completed with some kind of - * error. See __smu_cmn_reg2errno() for details of the -errno. + * Return 0 on success, -errno when a problem is encountered sending + * message or receiving reply. If there is a PCI bus recovery or + * the destination is a virtual GPU which does not allow this message + * type, the message is simply dropped and success is also returned. + * See __smu_cmn_reg2errno() for details of the -errno. * * If we weren't able to send the message to the SMU, we also print * the error to the standard log. |