[PATCH] drm/amdgpu: Retry i2c transfer once if it fails on SMU13.0.6

[Kent Russell]

During init, there can be some collisions on the i2c bus that result in
the EEPROM read failing. This has been mitigated in the PMFW to a
degree, but there is still a small chance that the bus will be busy.
When the read fails during RAS init, that disables page retirement
altogether, which is obviously not ideal. To try to avoid that
situation, set the eeprom_read function to retry once if the first read
fails, specifically for smu_v13_0_6.

Signed-off-by: Kent Russell <kent.russell at amd.com>
---
 drivers/gpu/drm/amd/pm/swsmu/smu13/smu_v13_0_6_ppt.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/amd/pm/swsmu/smu13/smu_v13_0_6_ppt.c b/drivers/gpu/drm/amd/pm/swsmu/smu13/smu_v13_0_6_ppt.c
index 9974c9f8135e..65d24c2f7e24 100644
--- a/drivers/gpu/drm/amd/pm/swsmu/smu13/smu_v13_0_6_ppt.c
+++ b/drivers/gpu/drm/amd/pm/swsmu/smu13/smu_v13_0_6_ppt.c
@@ -2107,8 +2107,12 @@ static int smu_v13_0_6_i2c_xfer(struct i2c_adapter *i2c_adap,
 	}
 	mutex_lock(&adev->pm.mutex);
 	r = smu_v13_0_6_request_i2c_xfer(smu, req);
-	if (r)
-		goto fail;
+	if (r) {
+		/* Rrtry once, in case of an i2c collision */
+		r = smu_v13_0_6_request_i2c_xfer(smu, req);
+		if (r) 
+			goto fail;
+	}
 
 	for (c = i = 0; i < num_msgs; i++) {
 		if (!(msg[i].flags & I2C_M_RD)) {
-- 
2.34.1