Re: [PATCH] gpu: drm/panel: Optimize the workflow of s6d7aa0_lock

From: Neil Armstrong
Date: Wed May 31 2023 - 07:55:56 EST


Hi,

On 31/05/2023 13:07, Lu Hongfei wrote:
This patch optimized s6d7aa0_lock's workflow.
Once mipi_dsi_dcs_write_seq failed, s6d7aa0_lock return immediately
and no further actions will be taken.

Fixes: 6810bb390282 ("drm/panel: Add Samsung S6D7AA0 panel controller driver")

Signed-off-by: Lu Hongfei <luhongfei@xxxxxxxx>
---
drivers/gpu/drm/panel/panel-samsung-s6d7aa0.c | 30 ++++++++++++++-----
1 file changed, 22 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/panel/panel-samsung-s6d7aa0.c b/drivers/gpu/drm/panel/panel-samsung-s6d7aa0.c
index 102e1fc7ee38..f98df32d1c55
--- a/drivers/gpu/drm/panel/panel-samsung-s6d7aa0.c
+++ b/drivers/gpu/drm/panel/panel-samsung-s6d7aa0.c
@@ -69,15 +69,29 @@ static int s6d7aa0_lock(struct s6d7aa0 *ctx, bool lock)
int ret = 0;
if (lock) {
- mipi_dsi_dcs_write_seq(dsi, MCS_PASSWD1, 0xa5, 0xa5);
- mipi_dsi_dcs_write_seq(dsi, MCS_PASSWD2, 0xa5, 0xa5);
- if (ctx->desc->use_passwd3)
- mipi_dsi_dcs_write_seq(dsi, MCS_PASSWD3, 0x5a, 0x5a);
+ ret = mipi_dsi_dcs_write_seq(dsi, MCS_PASSWD1, 0xa5, 0xa5);
+ if (ret < 0)
+ return ret;

mipi_dsi_dcs_write_seq() is a macro that already calls "return ret" on error,
so this is wrong, and there's nothing wrong with the currently upstream driver.

Neil

+ ret = mipi_dsi_dcs_write_seq(dsi, MCS_PASSWD2, 0xa5, 0xa5);
+ if (ret < 0)
+ return ret;
+ if (ctx->desc->use_passwd3) {
+ ret = mipi_dsi_dcs_write_seq(dsi, MCS_PASSWD3, 0x5a, 0x5a);
+ if (ret < 0)
+ return ret;
+ }
} else {
- mipi_dsi_dcs_write_seq(dsi, MCS_PASSWD1, 0x5a, 0x5a);
- mipi_dsi_dcs_write_seq(dsi, MCS_PASSWD2, 0x5a, 0x5a);
- if (ctx->desc->use_passwd3)
- mipi_dsi_dcs_write_seq(dsi, MCS_PASSWD3, 0xa5, 0xa5);
+ ret = mipi_dsi_dcs_write_seq(dsi, MCS_PASSWD1, 0x5a, 0x5a);
+ if (ret < 0)
+ return ret;
+ ret = mipi_dsi_dcs_write_seq(dsi, MCS_PASSWD2, 0x5a, 0x5a);
+ if (ret < 0)
+ return ret;
+ if (ctx->desc->use_passwd3) {
+ ret = mipi_dsi_dcs_write_seq(dsi, MCS_PASSWD3, 0xa5, 0xa5);
+ if (ret < 0)
+ return ret;
+ }
}
return ret;