Re: [PATCH 3/7] drm/msm/dp: Remove dead code related to downstream cap info

From: Kuogee Hsieh
Date: Thu Aug 31 2023 - 16:28:45 EST



On 8/29/2023 11:47 AM, Stephen Boyd wrote:
We read the downstream port count and capability info but never use it
anywhere. Remove 'ds_port_cnt' and 'ds_cap_info' and any associated code
from this driver. Fold the check for 'dfp_present' into a call to
drm_dp_is_branch() at the one place it is used to get rid of any member
storage related to downstream ports.

Cc: Vinod Polimera <quic_vpolimer@xxxxxxxxxxx>
Cc: Kuogee Hsieh <quic_khsieh@xxxxxxxxxxx>
Signed-off-by: Stephen Boyd <swboyd@xxxxxxxxxxxx>
Tested-by: Kuogee Hsieh <quic_khsieh@xxxxxxxxxxx>
Reviewed-by: Kuogee Hsieh <quic_khsieh@xxxxxxxxxxx>
---
drivers/gpu/drm/msm/dp/dp_panel.c | 25 +++----------------------
drivers/gpu/drm/msm/dp/dp_panel.h | 6 ------
2 files changed, 3 insertions(+), 28 deletions(-)

diff --git a/drivers/gpu/drm/msm/dp/dp_panel.c b/drivers/gpu/drm/msm/dp/dp_panel.c
index a0523b18b9e9..9fb4e963fefb 100644
--- a/drivers/gpu/drm/msm/dp/dp_panel.c
+++ b/drivers/gpu/drm/msm/dp/dp_panel.c
@@ -43,9 +43,7 @@ static void dp_panel_read_psr_cap(struct dp_panel_private *panel)
static int dp_panel_read_dpcd(struct dp_panel *dp_panel)
{
- int rc = 0;
- size_t len;
- ssize_t rlen;
+ int rc;
struct dp_panel_private *panel;
struct dp_link_info *link_info;
u8 *dpcd, major, minor;
@@ -79,25 +77,8 @@ static int dp_panel_read_dpcd(struct dp_panel *dp_panel)
if (drm_dp_enhanced_frame_cap(dpcd))
link_info->capabilities |= DP_LINK_CAP_ENHANCED_FRAMING;
- dp_panel->dfp_present = dpcd[DP_DOWNSTREAMPORT_PRESENT];
- dp_panel->dfp_present &= DP_DWN_STRM_PORT_PRESENT;
-
- if (dp_panel->dfp_present && (dpcd[DP_DPCD_REV] > 0x10)) {
- dp_panel->ds_port_cnt = dpcd[DP_DOWN_STREAM_PORT_COUNT];
- dp_panel->ds_port_cnt &= DP_PORT_COUNT_MASK;
- len = DP_DOWNSTREAM_PORTS * DP_DOWNSTREAM_CAP_SIZE;
-
- rlen = drm_dp_dpcd_read(panel->aux,
- DP_DOWNSTREAM_PORT_0, dp_panel->ds_cap_info, len);
- if (rlen < len) {
- DRM_ERROR("ds port status failed, rlen=%zd\n", rlen);
- rc = -EINVAL;
- goto end;
- }
- }
-
dp_panel_read_psr_cap(panel);
-end:
+
return rc;
}
@@ -173,7 +154,7 @@ int dp_panel_read_sink_caps(struct dp_panel *dp_panel,
return -EINVAL;
}
- if (dp_panel->dfp_present) {
+ if (drm_dp_is_branch(dp_panel->dpcd)) {
count = drm_dp_read_sink_count(panel->aux);
if (!count) {
DRM_ERROR("no downstream ports connected\n");
diff --git a/drivers/gpu/drm/msm/dp/dp_panel.h b/drivers/gpu/drm/msm/dp/dp_panel.h
index 6d733480a62d..3cb1f8dcfd3b 100644
--- a/drivers/gpu/drm/msm/dp/dp_panel.h
+++ b/drivers/gpu/drm/msm/dp/dp_panel.h
@@ -13,9 +13,6 @@
struct edid;
-#define DP_DOWNSTREAM_PORTS 4
-#define DP_DOWNSTREAM_CAP_SIZE 4
-
struct dp_display_mode {
struct drm_display_mode drm_mode;
u32 capabilities;
@@ -39,9 +36,6 @@ struct dp_panel_psr {
struct dp_panel {
/* dpcd raw data */
u8 dpcd[DP_RECEIVER_CAP_SIZE];
- u8 ds_cap_info[DP_DOWNSTREAM_PORTS * DP_DOWNSTREAM_CAP_SIZE];
- u32 ds_port_cnt;
- u32 dfp_present;
struct dp_link_info link_info;
struct drm_dp_desc desc;