diff options
| author | Michał Grzelak <michal.grzelak@intel.com> | 2026-04-16 18:37:44 +0200 |
|---|---|---|
| committer | Tvrtko Ursulin <tursulin@ursulin.net> | 2026-05-26 09:31:42 +0100 |
| commit | 202e77cf2e839e1adc804433322dc5c9ee511c9f (patch) | |
| tree | a16117bae152212c0991522fc4309d2577521231 | |
| parent | 5c4063c87a619e4df954c179d24628636f5db15f (diff) | |
drm/i915/aux: use polling when irqs are unavailable
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"")
Suggested-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Michał Grzelak <michal.grzelak@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patch.msgid.link/20260416163744.288107-1-michal.grzelak@intel.com
(cherry picked from commit 05e0550b65cd1604bd515fbc65f522bce4c10a87)
Signed-off-by: Tvrtko Ursulin <tursulin@ursulin.net>
| -rw-r--r-- | drivers/gpu/drm/i915/display/intel_dp_aux.c | 20 |
1 files 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 b20ec3e589fa..9c9b6410366d 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; } |