PTL with physically disconnected display was observed to have 40s longer
execution time when testing xe_fault_injection@xe_guc_mmio_send_recv.
The issue has not been seen when reverting commit 40a9f77a28fa ("Revert
"drm/i915/dp: change aux_ctl reg read to polling read"").
Apparently the configuration suffers from not having AUX enabled when
using interrupts. One probable cause can be xe enabling interrupts too
late: interrupts need memory allocations which currently can't be done
before the display FB takeover is done.
As for now, use polling for AUX in case interrupts are unavailable.
Fixes: 40a9f77a28fa ("Revert "drm/i915/dp: change aux_ctl reg read to polling
read"")
Cc: Ville Syrjälä <[email protected]>
Signed-off-by: Michał Grzelak <[email protected]>
---
drivers/gpu/drm/i915/display/intel_dp_aux.c | 20 ++++++++++++++++----
1 file changed, 16 insertions(+), 4 deletions(-)
diff --git a/drivers/gpu/drm/i915/display/intel_dp_aux.c
b/drivers/gpu/drm/i915/display/intel_dp_aux.c
index b20ec3e589fad..9c9b6410366d5 100644
--- a/drivers/gpu/drm/i915/display/intel_dp_aux.c
+++ b/drivers/gpu/drm/i915/display/intel_dp_aux.c
@@ -12,6 +12,7 @@
#include "intel_dp.h"
#include "intel_dp_aux.h"
#include "intel_dp_aux_regs.h"
+#include "intel_parent.h"
#include "intel_pps.h"
#include "intel_quirks.h"
#include "intel_tc.h"
@@ -60,18 +61,29 @@ intel_dp_aux_wait_done(struct intel_dp *intel_dp)
struct intel_display *display = to_intel_display(intel_dp);
i915_reg_t ch_ctl = intel_dp->aux_ch_ctl_reg(intel_dp);
const unsigned int timeout_ms = 10;
+ bool done = true;
u32 status;
- bool done;
+ int ret;
+ if (intel_parent_irq_enabled(display)) {
#define C (((status = intel_de_read_notrace(display, ch_ctl)) &
DP_AUX_CH_CTL_SEND_BUSY) == 0)
- done = wait_event_timeout(display->gmbus.wait_queue, C,
- msecs_to_jiffies_timeout(timeout_ms));
+ done = wait_event_timeout(display->gmbus.wait_queue, C,
+ msecs_to_jiffies_timeout(timeout_ms));
+
+#undef C
+ } else {
+ ret = intel_de_wait_ms(display, ch_ctl,
+ DP_AUX_CH_CTL_SEND_BUSY, 0,
+ timeout_ms, &status);
+
+ if (ret == -ETIMEDOUT)
+ done = false;
+ }
if (!done)
drm_err(display->drm,
"%s: did not complete or timeout within %ums (status
0x%08x)\n",
intel_dp->aux.name, timeout_ms, status);
-#undef C
return status;
}
--
2.45.2
