[PATCH 5.15 057/135] drm/msm/dp: dp_link_parse_sink_count() return immediately if aux read failed

Greg Kroah-Hartman
2022-06-27T11:40:18Z

From: Kuogee Hsieh <quic_khsieh@quicinc.com>

[ Upstream commit f61550b3864b9578527c28cf9c465316ac1566e1 ]

Add checking aux read/write status at both dp_link_parse_sink_count()
and dp_link_parse_sink_status_filed() to avoid long timeout delay if
dp aux read/write failed at timeout due to cable unplugged.

Changes in V4:
-- split this patch as stand alone patch

Changes in v5:
-- rebase on msm-next branch

Signed-off-by: Kuogee Hsieh <quic_khsieh@quicinc.com>

Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Tested-by: Stephen Boyd <swboyd@chromium.org>
Link: https://lore.kernel.org/r/1638985262-2072-1-git-send-email-quic_khsieh@quicinc.com
Signed-off-by: Rob Clark <robdclark@chromium.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/gpu/drm/msm/dp/dp_display.c | 12 +++++++++---
drivers/gpu/drm/msm/dp/dp_link.c | 19 ++++++++++++++-----
2 files changed, 23 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c
index a66ee63253a3..32b8dbb917bf 100644
--- a/drivers/gpu/drm/msm/dp/dp_display.c
+++ b/drivers/gpu/drm/msm/dp/dp_display.c
@@ -712,9 +712,15 @@ static int dp_irq_hpd_handle(struct dp_display_private *dp, u32 data)
return 0;
}

- ret = dp_display_usbpd_attention_cb(&dp->pdev->dev);
- if (ret == -ECONNRESET) { /* cable unplugged */
- dp->core_initialized = false;
+ /*
+ * dp core (ahb/aux clks) must be initialized before
+ * irq_hpd be handled
+ */
+ if (dp->core_initialized) {
+ ret = dp_display_usbpd_attention_cb(&dp->pdev->dev);
+ if (ret == -ECONNRESET) { /* cable unplugged */
+ dp->core_initialized = false;
+ }
}
DRM_DEBUG_DP("hpd_state=%d\n", state);

diff --git a/drivers/gpu/drm/msm/dp/dp_link.c b/drivers/gpu/drm/msm/dp/dp_link.c
index a5bdfc5029de..d4d31e5bda07 100644
--- a/drivers/gpu/drm/msm/dp/dp_link.c
+++ b/drivers/gpu/drm/msm/dp/dp_link.c
@@ -737,18 +737,25 @@ static int dp_link_parse_sink_count(struct dp_link *dp_link)
return 0;
}

-static void dp_link_parse_sink_status_field(struct dp_link_private *link)
+static int dp_link_parse_sink_status_field(struct dp_link_private *link)
{
int len = 0;

link->prev_sink_count = link->dp_link.sink_count;
- dp_link_parse_sink_count(&link->dp_link);
+ len = dp_link_parse_sink_count(&link->dp_link);
+ if (len < 0) {
+ DRM_ERROR("DP parse sink count failed\n");
+ return len;
+ }

len = drm_dp_dpcd_read_link_status(link->aux,
link->link_status);
- if (len < DP_LINK_STATUS_SIZE)
+ if (len < DP_LINK_STATUS_SIZE) {
DRM_ERROR("DP link status read failed\n");
- dp_link_parse_request(link);
+ return len;
+ }
+
+ return dp_link_parse_request(link);
}

/**
@@ -1023,7 +1030,9 @@ int dp_link_process_request(struct dp_link *dp_link)

dp_link_reset_data(link);

- dp_link_parse_sink_status_field(link);
+ ret = dp_link_parse_sink_status_field(link);
+ if (ret)
+ return ret;

if (link->request.test_requested == DP_TEST_LINK_EDID_READ) {
dp_link->sink_request |= DP_TEST_LINK_EDID_READ;
--
2.35.1