From 5a9b0c7418448ed3766f61ba0a71d08f259c3181 Mon Sep 17 00:00:00 2001 From: Arun R Murthy Date: Wed, 21 Dec 2022 09:02:09 +0530 Subject: [PATCH] drm/i915/dp: change aux_ctl reg read to polling read The busy timeout logic checks for the AUX BUSY, then waits for the timeout period and then after timeout reads the register for BUSY or Success. Instead replace interrupt with polling so as to read the AUX CTL register often before the timeout period. Looks like there might be some issue with interrupt-on-read. Hence changing the logic to polling read. v2: replace interrupt with polling read v3: use usleep_rang instead of msleep, updated commit msg v4: use intel_wait_for_regiter internal function v5: use __intel_de_wait_for_register with 500us slow and 10ms fast timeout v6: check return value of __intel_de_wait_for_register v7: using default 2us for intel_de_wait_for_register Signed-off-by: Arun R Murthy Signed-off-by: Jani Nikula Link: https://patchwork.freedesktop.org/patch/msgid/20221221033209.1284435-1-arun.r.murthy@intel.com --- drivers/gpu/drm/i915/display/intel_dp_aux.c | 14 +++++--------- 1 file changed, 5 insertions(+), 9 deletions(-) diff --git a/drivers/gpu/drm/i915/display/intel_dp_aux.c b/drivers/gpu/drm/i915/display/intel_dp_aux.c index 91c93c9..5a176bf 100644 --- a/drivers/gpu/drm/i915/display/intel_dp_aux.c +++ b/drivers/gpu/drm/i915/display/intel_dp_aux.c @@ -41,20 +41,16 @@ intel_dp_aux_wait_done(struct intel_dp *intel_dp) i915_reg_t ch_ctl = intel_dp->aux_ch_ctl_reg(intel_dp); const unsigned int timeout_ms = 10; u32 status; - bool done; - -#define C (((status = intel_de_read_notrace(i915, ch_ctl)) & DP_AUX_CH_CTL_SEND_BUSY) == 0) - done = wait_event_timeout(i915->display.gmbus.wait_queue, C, - msecs_to_jiffies_timeout(timeout_ms)); + int ret; - /* just trace the final value */ - trace_i915_reg_rw(false, ch_ctl, status, sizeof(status), true); + ret = __intel_de_wait_for_register(i915, ch_ctl, + DP_AUX_CH_CTL_SEND_BUSY, 0, + 2, timeout_ms, &status); - if (!done) + if (ret == -ETIMEDOUT) drm_err(&i915->drm, "%s: did not complete or timeout within %ums (status 0x%08x)\n", intel_dp->aux.name, timeout_ms, status); -#undef C return status; } -- 2.7.4