From: "Leo (Sunpeng) Li" <sunpeng.li@amd.com>
Date: Tue, 26 Jun 2018 10:44:05 -0400
Subject: drm/amd/display: Right shift AUX reply value sooner than later
Git-commit: 3092108904461dd50b1502f3a2977a4259d91044
Patch-mainline: v4.19-rc1
References: FATE#326289 FATE#326079 FATE#326049 FATE#322398 FATE#326166
[Why]
There is no point in keeping the AUX reply value in the raw format as
returned from reading the AUX_SW_DATA register.
[How]
Shift it within read_channel_reply(), where the register is read, before
returning it.
Signed-off-by: Leo (Sunpeng) Li <sunpeng.li@amd.com>
Reviewed-by: Harry Wentland <Harry.Wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
drivers/gpu/drm/amd/display/dc/i2caux/dce110/aux_engine_dce110.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
--- a/drivers/gpu/drm/amd/display/dc/i2caux/dce110/aux_engine_dce110.c
+++ b/drivers/gpu/drm/amd/display/dc/i2caux/dce110/aux_engine_dce110.c
@@ -300,9 +300,10 @@ static int read_channel_reply(struct aux
AUX_SW_DATA_RW, 1);
REG_GET(AUX_SW_DATA, AUX_SW_DATA, &reply_result_32);
+ reply_result_32 = reply_result_32 >> 4;
*reply_result = (uint8_t)reply_result_32;
- if (reply_result_32 >> 4 == 0) { /* ACK */
+ if (reply_result_32 == 0) { /* ACK */
uint32_t i = 0;
/* First byte was already used to get the command status */
@@ -356,7 +357,6 @@ static void process_channel_reply(
return;
}
} else {
- reply_result = reply_result >> 4;
switch (reply_result) {
case 0: /* ACK */