linux-kernel - [PATCH v2 2/4] drm/msm/dp: Account for the timeout in wait_hpd

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Date: Fri, 15 Mar 2024 14:36:30 -0700
From: Douglas Anderson <dianders@...omium.org>
To: Rob Clark <robdclark@...il.com>,
	Abhinav Kumar <quic_abhinavk@...cinc.com>,
	Dmitry Baryshkov <dmitry.baryshkov@...aro.org>
Cc: Douglas Anderson <dianders@...omium.org>,
	Daniel Vetter <daniel@...ll.ch>,
	David Airlie <airlied@...il.com>,
	Kuogee Hsieh <quic_khsieh@...cinc.com>,
	Marijn Suijten <marijn.suijten@...ainline.org>,
	Sean Paul <sean@...rly.run>,
	dri-devel@...ts.freedesktop.org,
	freedreno@...ts.freedesktop.org,
	linux-arm-msm@...r.kernel.org,
	linux-kernel@...r.kernel.org
Subject: [PATCH v2 2/4] drm/msm/dp: Account for the timeout in wait_hpd_asserted() callback

The DP wait_hpd_asserted() callback is passed a timeout which
indicates how long we should wait for HPD. This timeout was being
ignored in the MSM DP implementation and instead a hardcoded 500 ms
timeout was used. Fix it to use the proper timeout.

As part of this we move the hardcoded 500 ms number into the AUX
transfer function, which isn't given a timeout. The wait in the AUX
transfer function will be removed in a future commit.

Fixes: e2969ee30252 ("drm/msm/dp: move of_dp_aux_populate_bus() to eDP probe()")
Signed-off-by: Douglas Anderson <dianders@...omium.org>
---

(no changes since v1)

 drivers/gpu/drm/msm/dp/dp_aux.c     | 5 +++--
 drivers/gpu/drm/msm/dp/dp_catalog.c | 7 ++++---
 drivers/gpu/drm/msm/dp/dp_catalog.h | 3 ++-
 3 files changed, 9 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/msm/dp/dp_aux.c b/drivers/gpu/drm/msm/dp/dp_aux.c
index e67a80d56948..75c51f3ee106 100644
--- a/drivers/gpu/drm/msm/dp/dp_aux.c
+++ b/drivers/gpu/drm/msm/dp/dp_aux.c
@@ -322,7 +322,8 @@ static ssize_t dp_aux_transfer(struct drm_dp_aux *dp_aux,
 	 * avoid ever doing the extra long wait for DP.
 	 */
 	if (aux->is_edp) {
-		ret = dp_catalog_aux_wait_for_hpd_connect_state(aux->catalog);
+		ret = dp_catalog_aux_wait_for_hpd_connect_state(aux->catalog,
+								500000);
 		if (ret) {
 			DRM_DEBUG_DP("Panel not ready for aux transactions\n");
 			goto exit;
@@ -530,7 +531,7 @@ static int dp_wait_hpd_asserted(struct drm_dp_aux *dp_aux,
 	aux = container_of(dp_aux, struct dp_aux_private, dp_aux);
 
 	pm_runtime_get_sync(aux->dev);
-	ret = dp_catalog_aux_wait_for_hpd_connect_state(aux->catalog);
+	ret = dp_catalog_aux_wait_for_hpd_connect_state(aux->catalog, wait_us);
 	pm_runtime_put_sync(aux->dev);
 
 	return ret;
diff --git a/drivers/gpu/drm/msm/dp/dp_catalog.c b/drivers/gpu/drm/msm/dp/dp_catalog.c
index 5142aeb705a4..944ccb74f06c 100644
--- a/drivers/gpu/drm/msm/dp/dp_catalog.c
+++ b/drivers/gpu/drm/msm/dp/dp_catalog.c
@@ -253,17 +253,18 @@ void dp_catalog_aux_update_cfg(struct dp_catalog *dp_catalog)
 	phy_calibrate(phy);
 }
 
-int dp_catalog_aux_wait_for_hpd_connect_state(struct dp_catalog *dp_catalog)
+int dp_catalog_aux_wait_for_hpd_connect_state(struct dp_catalog *dp_catalog,
+					      unsigned long wait_us)
 {
 	u32 state;
 	struct dp_catalog_private *catalog = container_of(dp_catalog,
 				struct dp_catalog_private, dp_catalog);
 
-	/* poll for hpd connected status every 2ms and timeout after 500ms */
+	/* poll for hpd connected status every 2ms and timeout after wait_us */
 	return readl_poll_timeout(catalog->io->dp_controller.aux.base +
 				REG_DP_DP_HPD_INT_STATUS,
 				state, state & DP_DP_HPD_STATE_STATUS_CONNECTED,
-				2000, 500000);
+				min(wait_us, 2000), wait_us);
 }
 
 static void dump_regs(void __iomem *base, int len)
diff --git a/drivers/gpu/drm/msm/dp/dp_catalog.h b/drivers/gpu/drm/msm/dp/dp_catalog.h
index 38786e855b51..d116df1fc3ac 100644
--- a/drivers/gpu/drm/msm/dp/dp_catalog.h
+++ b/drivers/gpu/drm/msm/dp/dp_catalog.h
@@ -85,7 +85,8 @@ int dp_catalog_aux_clear_hw_interrupts(struct dp_catalog *dp_catalog);
 void dp_catalog_aux_reset(struct dp_catalog *dp_catalog);
 void dp_catalog_aux_enable(struct dp_catalog *dp_catalog, bool enable);
 void dp_catalog_aux_update_cfg(struct dp_catalog *dp_catalog);
-int dp_catalog_aux_wait_for_hpd_connect_state(struct dp_catalog *dp_catalog);
+int dp_catalog_aux_wait_for_hpd_connect_state(struct dp_catalog *dp_catalog,
+					      unsigned long wait_us);
 u32 dp_catalog_aux_get_irq(struct dp_catalog *dp_catalog);
 
 /* DP Controller APIs */
-- 
2.44.0.291.gc1ea87d7ee-goog