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drm/i915/guc: Don't abort on CTB_UNUSED status

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When the KMD sends a CLIENT_RESET request to GuC (as part of the
suspend sequence), GuC will mark the CTB buffer as 'UNUSED'. If the
KMD then checked the CTB queue, it would see a non-zero status value
and report the buffer as corrupted.

Technically, no G2H messages should be received once the CLIENT_RESET
has been sent. However, if a context was outstanding on an engine then
it would get reset and a reset notification would be sent. So, don't
actually treat UNUSED as a catastrophic error. Just flag it up as
unexpected and keep going.

Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Reviewed-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220728024225.2363663-7-John.C.Harrison@Intel.com
This commit is contained in:
John Harrison 2022-07-27 19:42:25 -07:00
parent 52d4cfdc24
commit dd9d3cbe9e
2 changed files with 21 additions and 5 deletions
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8
drivers/gpu/drm/i915/gt/uc/abi/guc_communication_ctb_abi.h
View File

@ -37,6 +37,7 @@
* | | | - _`GUC_CTB_STATUS_OVERFLOW` = 1 (head/tail too large) |
* | | | - _`GUC_CTB_STATUS_UNDERFLOW` = 2 (truncated message) |
* | | | - _`GUC_CTB_STATUS_MISMATCH` = 4 (head/tail modified) |
* | | | - _`GUC_CTB_STATUS_UNUSED` = 8 (CTB is not in use) |
* +---+-------+--------------------------------------------------------------+
* |...| | RESERVED = MBZ |
* +---+-------+--------------------------------------------------------------+
@ -49,9 +50,10 @@ struct guc_ct_buffer_desc {
u32 tail;
u32 status;
#define GUC_CTB_STATUS_NO_ERROR 0
#define GUC_CTB_STATUS_OVERFLOW (1 << 0)
#define GUC_CTB_STATUS_UNDERFLOW (1 << 1)
#define GUC_CTB_STATUS_MISMATCH (1 << 2)
#define GUC_CTB_STATUS_OVERFLOW BIT(0)
#define GUC_CTB_STATUS_UNDERFLOW BIT(1)
#define GUC_CTB_STATUS_MISMATCH BIT(2)
#define GUC_CTB_STATUS_UNUSED BIT(3)
u32 reserved[13];
} __packed;
static_assert(sizeof(struct guc_ct_buffer_desc) == 64);

18
drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c
View File

@ -829,8 +829,22 @@ static int ct_read(struct intel_guc_ct *ct, struct ct_incoming_msg **msg)
if (unlikely(ctb->broken))
return -EPIPE;
if (unlikely(desc->status))
goto corrupted;
if (unlikely(desc->status)) {
u32 status = desc->status;
if (status & GUC_CTB_STATUS_UNUSED) {
/*
* Potentially valid if a CLIENT_RESET request resulted in
* contexts/engines being reset. But should never happen as
* no contexts should be active when CLIENT_RESET is sent.
*/
CT_ERROR(ct, "Unexpected G2H after GuC has stopped!\n");
status &= ~GUC_CTB_STATUS_UNUSED;
}
if (status)
goto corrupted;
}
GEM_BUG_ON(head > size);