From 82cec24bc1dc7fadc998abc6ed0742f605426be8 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ville=20Syrj=C3=A4l=C3=A4?= <ville.syrjala@linux.intel.com>
Date: Fri, 17 Apr 2020 18:27:33 +0300
Subject: drm/i915: Flatten intel_dp_check_mst_status() a bit
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Git-commit: 3c0ec2c2d5948356a22c8f1c08a8087b12a303e7
Patch-mainline: v5.8-rc1
References: jsc#SLE-12680, jsc#SLE-12880, jsc#SLE-12882, jsc#SLE-12883, jsc#SLE-13496, jsc#SLE-15322
Make intel_dp_check_mst_status() somewhat legible by humans.
Note that the return value of drm_dp_mst_hpd_irq() is always
either 0 or -ENOMEM, and we never did anything with the latter
so we can just ignore the whole thing.
We can also get rid of the direct drm_dp_mst_topology_mgr_set_mst(false)
call since returning -EINVAL causes the caller to do the very same call
for us.
Cc: Lyude Paul <lyude@redhat.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200417152734.464-1-ville.syrjala@linux.intel.com
Reviewed-by: Lyude Paul <lyude@redhat.com>
Signed-off-by: Patrik Jakobsson <pjakobsson@suse.de>
---
drivers/gpu/drm/i915/display/intel_dp.c | 86 ++++++++++++-------------
1 file changed, 40 insertions(+), 46 deletions(-)
diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
index a71d29136595..ca2193c6f7f1 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -5625,61 +5625,55 @@ static int
intel_dp_check_mst_status(struct intel_dp *intel_dp)
{
struct drm_i915_private *i915 = dp_to_i915(intel_dp);
- bool bret;
- if (intel_dp->is_mst) {
- u8 esi[DP_DPRX_ESI_LEN] = { 0 };
- int ret = 0;
+ if (!intel_dp->is_mst)
+ return -EINVAL;
+
+ WARN_ON_ONCE(intel_dp->active_mst_links < 0);
+
+ for (;;) {
+ u8 esi[DP_DPRX_ESI_LEN] = {};
+ bool bret, handled;
int retry;
- bool handled;
- WARN_ON_ONCE(intel_dp->active_mst_links < 0);
bret = intel_dp_get_sink_irq_esi(intel_dp, esi);
-go_again:
- if (bret == true) {
-
- /* check link status - esi[10] = 0x200c */
- if (intel_dp->active_mst_links > 0 &&
- !drm_dp_channel_eq_ok(&esi[10], intel_dp->lane_count)) {
- drm_dbg_kms(&i915->drm,
- "channel EQ not ok, retraining\n");
- intel_dp_start_link_train(intel_dp);
- intel_dp_stop_link_train(intel_dp);
- }
+ if (!bret) {
+ drm_dbg_kms(&i915->drm,
+ "failed to get ESI - device may have failed\n");
+ return -EINVAL;
+ }
- drm_dbg_kms(&i915->drm, "got esi %3ph\n", esi);
- ret = drm_dp_mst_hpd_irq(&intel_dp->mst_mgr, esi, &handled);
-
- if (handled) {
- for (retry = 0; retry < 3; retry++) {
- int wret;
- wret = drm_dp_dpcd_write(&intel_dp->aux,
- DP_SINK_COUNT_ESI+1,
- &esi[1], 3);
- if (wret == 3) {
- break;
- }
- }
+ /* check link status - esi[10] = 0x200c */
+ /*
+ * FIXME kill this and use the SST retraining approach
+ * for MST as well.
+ */
+ if (intel_dp->active_mst_links > 0 &&
+ !drm_dp_channel_eq_ok(&esi[10], intel_dp->lane_count)) {
+ drm_dbg_kms(&i915->drm,
+ "channel EQ not ok, retraining\n");
+ intel_dp_start_link_train(intel_dp);
+ intel_dp_stop_link_train(intel_dp);
+ }
- bret = intel_dp_get_sink_irq_esi(intel_dp, esi);
- if (bret == true) {
- drm_dbg_kms(&i915->drm,
- "got esi2 %3ph\n", esi);
- goto go_again;
- }
- } else
- ret = 0;
+ drm_dbg_kms(&i915->drm, "got esi %3ph\n", esi);
- return ret;
- } else {
- drm_dbg_kms(&i915->drm,
- "failed to get ESI - device may have failed\n");
- intel_dp->is_mst = false;
- drm_dp_mst_topology_mgr_set_mst(&intel_dp->mst_mgr,
- intel_dp->is_mst);
+ drm_dp_mst_hpd_irq(&intel_dp->mst_mgr, esi, &handled);
+ if (!handled)
+ break;
+
+ for (retry = 0; retry < 3; retry++) {
+ int wret;
+
+ wret = drm_dp_dpcd_write(&intel_dp->aux,
+ DP_SINK_COUNT_ESI+1,
+ &esi[1], 3);
+ if (wret == 3)
+ break;
}
}
- return -EINVAL;
+
+ return 0;
}
static bool
--
2.28.0