[PATCH 5.12 244/384] drm/amd/display: Fix debugfs link_settings entry

From: Greg Kroah-Hartman
Date: Mon May 10 2021 - 08:26:22 EST


From: Fangzhi Zuo <Jerry.Zuo@xxxxxxx>

[ Upstream commit c006a1c00de29e8cdcde1d0254ac23433ed3fee9 ]

1. Catch invalid link_rate and link_count settings
2. Call dc interface to overwrite preferred link settings, and wait
until next stream update to apply the new settings.

Tested-by: Daniel Wheeler <daniel.wheeler@xxxxxxx>
Signed-off-by: Fangzhi Zuo <Jerry.Zuo@xxxxxxx>
Reviewed-by: Nicholas Kazlauskas <Nicholas.Kazlauskas@xxxxxxx>
Acked-by: Solomon Chiu <solomon.chiu@xxxxxxx>
Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
.../drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c | 15 ++++++++-------
1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c
index 360952129b6d..29139b34dbe2 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c
@@ -150,7 +150,7 @@ static int parse_write_buffer_into_params(char *wr_buf, uint32_t wr_buf_size,
*
* --- to get dp configuration
*
- * cat link_settings
+ * cat /sys/kernel/debug/dri/0/DP-x/link_settings
*
* It will list current, verified, reported, preferred dp configuration.
* current -- for current video mode
@@ -163,7 +163,7 @@ static int parse_write_buffer_into_params(char *wr_buf, uint32_t wr_buf_size,
* echo <lane_count> <link_rate> > link_settings
*
* for example, to force to 2 lane, 2.7GHz,
- * echo 4 0xa > link_settings
+ * echo 4 0xa > /sys/kernel/debug/dri/0/DP-x/link_settings
*
* spread_spectrum could not be changed dynamically.
*
@@ -171,7 +171,7 @@ static int parse_write_buffer_into_params(char *wr_buf, uint32_t wr_buf_size,
* done. please check link settings after force operation to see if HW get
* programming.
*
- * cat link_settings
+ * cat /sys/kernel/debug/dri/0/DP-x/link_settings
*
* check current and preferred settings.
*
@@ -255,7 +255,7 @@ static ssize_t dp_link_settings_write(struct file *f, const char __user *buf,
int max_param_num = 2;
uint8_t param_nums = 0;
long param[2];
- bool valid_input = false;
+ bool valid_input = true;

if (size == 0)
return -EINVAL;
@@ -282,9 +282,9 @@ static ssize_t dp_link_settings_write(struct file *f, const char __user *buf,
case LANE_COUNT_ONE:
case LANE_COUNT_TWO:
case LANE_COUNT_FOUR:
- valid_input = true;
break;
default:
+ valid_input = false;
break;
}

@@ -294,9 +294,9 @@ static ssize_t dp_link_settings_write(struct file *f, const char __user *buf,
case LINK_RATE_RBR2:
case LINK_RATE_HIGH2:
case LINK_RATE_HIGH3:
- valid_input = true;
break;
default:
+ valid_input = false;
break;
}

@@ -310,10 +310,11 @@ static ssize_t dp_link_settings_write(struct file *f, const char __user *buf,
* spread spectrum will not be changed
*/
prefer_link_settings.link_spread = link->cur_link_settings.link_spread;
+ prefer_link_settings.use_link_rate_set = false;
prefer_link_settings.lane_count = param[0];
prefer_link_settings.link_rate = param[1];

- dc_link_set_preferred_link_settings(dc, &prefer_link_settings, link);
+ dc_link_set_preferred_training_settings(dc, &prefer_link_settings, NULL, link, true);

kfree(wr_buf);
return size;
--
2.30.2