From: Lyude <cpaul@redhat.com>
Date: Sat, 6 Aug 2016 00:30:37 +0000 (-0400)
Subject: drm/amdgpu: Don't retry 7 times in amdgpu_atombios_dp_get_dpcd()
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=14a2fb487bed51d6020ed5d950e9f2cf17b5421b;p=GitHub%2FLineageOS%2Fandroid_kernel_motorola_exynos9610.git

drm/amdgpu: Don't retry 7 times in amdgpu_atombios_dp_get_dpcd()

When this code was written, we didn't retry DP aux transactions on any
error, which required retrying important transactions like this in
individual drivers. Since that's no longer the case, retrying here is
not necessary. As well, we retry any aux transaction on any error 32
times. 7 * 32 = 224, which means this loop causes us to retry grabbing
the dpcd 224 times. This is definitely far more then we actually need to
do.

Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Lyude <cpaul@redhat.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
---

diff --git a/drivers/gpu/drm/amd/amdgpu/atombios_dp.c b/drivers/gpu/drm/amd/amdgpu/atombios_dp.c
index 166dc7bdcfee..f81068ba4cc6 100644
--- a/drivers/gpu/drm/amd/amdgpu/atombios_dp.c
+++ b/drivers/gpu/drm/amd/amdgpu/atombios_dp.c
@@ -338,22 +338,21 @@ int amdgpu_atombios_dp_get_dpcd(struct amdgpu_connector *amdgpu_connector)
 {
 	struct amdgpu_connector_atom_dig *dig_connector = amdgpu_connector->con_priv;
 	u8 msg[DP_DPCD_SIZE];
-	int ret, i;
+	int ret;
 
-	for (i = 0; i < 7; i++) {
-		ret = drm_dp_dpcd_read(&amdgpu_connector->ddc_bus->aux, DP_DPCD_REV, msg,
-				       DP_DPCD_SIZE);
-		if (ret == DP_DPCD_SIZE) {
-			memcpy(dig_connector->dpcd, msg, DP_DPCD_SIZE);
+	ret = drm_dp_dpcd_read(&amdgpu_connector->ddc_bus->aux, DP_DPCD_REV,
+			       msg, DP_DPCD_SIZE);
+	if (ret == DP_DPCD_SIZE) {
+		memcpy(dig_connector->dpcd, msg, DP_DPCD_SIZE);
 
-			DRM_DEBUG_KMS("DPCD: %*ph\n", (int)sizeof(dig_connector->dpcd),
-				      dig_connector->dpcd);
+		DRM_DEBUG_KMS("DPCD: %*ph\n", (int)sizeof(dig_connector->dpcd),
+			      dig_connector->dpcd);
 
-			amdgpu_atombios_dp_probe_oui(amdgpu_connector);
+		amdgpu_atombios_dp_probe_oui(amdgpu_connector);
 
-			return 0;
-		}
+		return 0;
 	}
+
 	dig_connector->dpcd[0] = 0;
 	return -EINVAL;
 }