[PATCH 26/41] drm/bridge: analogix_dp: Reset aux channel if an error occurred

From: Sean Paul <seanpaul-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org>
To: linux-rockchip-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org,
	dri-devel-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org
Cc: "Archit Taneja" <architt-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>,
	"征增 王" <wzz-TNX95d0MmH7DzftRWevZcw@public.gmane.org>,
	"Lin Huang" <hl-TNX95d0MmH7DzftRWevZcw@public.gmane.org>,
	"Tomeu Vizoso"
	<tomeu.vizoso-ZGY8ohtN/8qB+jHODAdFcQ@public.gmane.org>,
	"David Airlie" <airlied-cv59FeDIM0c@public.gmane.org>,
	"Douglas Anderson"
	<dianders-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org>,
	"Sean Paul" <seanpaul-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org>,
	"Yakir Yang" <ykk-TNX95d0MmH7DzftRWevZcw@public.gmane.org>,
	"Heiko Stuebner" <heiko-4mtYJXux2i+zQB+pC5nmwQ@public.gmane.org>
Subject: [PATCH 26/41] drm/bridge: analogix_dp: Reset aux channel if an error occurred
Date: Thu,  9 Mar 2017 23:32:41 -0500	[thread overview]
Message-ID: <20170310043305.17216-27-seanpaul@chromium.org> (raw)
In-Reply-To: <20170310043305.17216-1-seanpaul-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org>

From: Lin Huang <hl@rock-chips.com>

AUX errors are caused by many different reasons. We may not know what
happened in aux channel on failure, so let's reset aux channel if some
errors occurred.

Cc: 征增 王 <wzz@rock-chips.com>
Cc: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Lin Huang <hl@rock-chips.com>
Signed-off-by: Sean Paul <seanpaul@chromium.org>
---
 drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c | 18 ++++++++++++++----
 1 file changed, 14 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c b/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c
index 377bee4e20fd..1cb57e528ec8 100644
--- a/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c
+++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c
@@ -465,6 +465,10 @@ void analogix_dp_init_aux(struct analogix_dp_device *dp)
 	reg = RPLY_RECEIV | AUX_ERR;
 	writel(reg, dp->reg_base + ANALOGIX_DP_INT_STA);
 
+	analogix_dp_set_analog_power_down(dp, AUX_BLOCK, true);
+	usleep_range(10, 11);
+	analogix_dp_set_analog_power_down(dp, AUX_BLOCK, false);
+
 	analogix_dp_reset_aux(dp);
 
 	/* Disable AUX transaction H/W retry */
@@ -1158,7 +1162,7 @@ ssize_t analogix_dp_transfer(struct analogix_dp_device *dp,
 				 reg, !(reg & AUX_EN), 25, 500 * 1000);
 	if (ret) {
 		dev_err(dp->dev, "AUX CH enable timeout!\n");
-		return -ETIMEDOUT;
+		goto aux_error;
 	}
 
 	/* TODO: Wait for an interrupt instead of looping? */
@@ -1167,7 +1171,7 @@ ssize_t analogix_dp_transfer(struct analogix_dp_device *dp,
 				 reg, reg & RPLY_RECEIV, 10, 20 * 1000);
 	if (ret) {
 		dev_err(dp->dev, "AUX CH cmd reply timeout!\n");
-		return -ETIMEDOUT;
+		goto aux_error;
 	}
 
 	/* Clear interrupt source for AUX CH command reply */
@@ -1177,7 +1181,7 @@ ssize_t analogix_dp_transfer(struct analogix_dp_device *dp,
 	reg = readl(dp->reg_base + ANALOGIX_DP_INT_STA);
 	if (reg & AUX_ERR) {
 		writel(AUX_ERR, dp->reg_base + ANALOGIX_DP_INT_STA);
-		return -EREMOTEIO;
+		goto aux_error;
 	}
 
 	/* Check AUX CH error access status */
@@ -1185,7 +1189,7 @@ ssize_t analogix_dp_transfer(struct analogix_dp_device *dp,
 	if ((reg & AUX_STATUS_MASK)) {
 		dev_err(dp->dev, "AUX CH error happened: %d\n\n",
 			reg & AUX_STATUS_MASK);
-		return -EREMOTEIO;
+		goto aux_error;
 	}
 
 	if (msg->request & DP_AUX_I2C_READ) {
@@ -1211,4 +1215,10 @@ ssize_t analogix_dp_transfer(struct analogix_dp_device *dp,
 		msg->reply = DP_AUX_NATIVE_REPLY_ACK;
 
 	return num_transferred > 0 ? num_transferred : -EBUSY;
+
+aux_error:
+	/* if aux err happen, reset aux */
+	analogix_dp_init_aux(dp);
+
+	return -EREMOTEIO;
 }
-- 
2.12.0.246.ga2ecc84866-goog


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