diff options
| author | Shashank Sharma <shashank.sharma@intel.com> | 2017-10-12 19:40:08 +0300 |
|---|---|---|
| committer | Jani Nikula <jani.nikula@intel.com> | 2017-10-13 12:13:54 +0300 |
| commit | f687e25a7a245952349f1f9f9cc238ac5a3be258 (patch) | |
| tree | 4945226440b6cdf888b129f0184a48a49ae0e06e /drivers/gpu | |
| parent | 8f5f63d558b979402ae48f3df2f7bc3589531e28 (diff) | |
| download | linux-f687e25a7a245952349f1f9f9cc238ac5a3be258.tar.xz | |
drm: Add retries for lspcon mode detection
From the CI builds, its been observed that during a driver
reload/insert, dp dual mode read function sometimes fails to
read from LSPCON device over i2c-over-aux channel.
This patch:
- adds some delay and few retries, allowing a scope for these
devices to settle down and respond.
- changes one error log's level from ERROR->DEBUG as we want
to call it an error only after all the retries are exhausted.
V2: Addressed review comments from Jani (for loop for retry)
V3: Addressed review comments from Imre (break on partial read too)
V3: Addressed review comments from Ville/Imre (Add the retries
exclusively for LSPCON, not for all dp_dual_mode devices)
V4: Added r-b from Imre, sending it to dri-devel (Jani)
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=102294
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=102295
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=102359
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=103186
Cc: Ville Syrjala <ville.syrjala@linux.intel.com>
Cc: Imre Deak <imre.deak@intel.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Reviewed-by: Imre Deak <imre.deak@intel.com>
Acked-by: Dave Airlie <airlied@gmail.com>
Signed-off-by: Shashank Sharma <shashank.sharma@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1507826408-19322-1-git-send-email-shashank.sharma@intel.com
Diffstat (limited to 'drivers/gpu')
| -rw-r--r-- | drivers/gpu/drm/drm_dp_dual_mode_helper.c | 16 |
1 files changed, 13 insertions, 3 deletions
diff --git a/drivers/gpu/drm/drm_dp_dual_mode_helper.c b/drivers/gpu/drm/drm_dp_dual_mode_helper.c index 0ef9011a1856..02a50929af67 100644 --- a/drivers/gpu/drm/drm_dp_dual_mode_helper.c +++ b/drivers/gpu/drm/drm_dp_dual_mode_helper.c @@ -410,6 +410,7 @@ int drm_lspcon_get_mode(struct i2c_adapter *adapter, { u8 data; int ret = 0; + int retry; if (!mode) { DRM_ERROR("NULL input\n"); @@ -417,10 +418,19 @@ int drm_lspcon_get_mode(struct i2c_adapter *adapter, } /* Read Status: i2c over aux */ - ret = drm_dp_dual_mode_read(adapter, DP_DUAL_MODE_LSPCON_CURRENT_MODE, - &data, sizeof(data)); + for (retry = 0; retry < 6; retry++) { + if (retry) + usleep_range(500, 1000); + + ret = drm_dp_dual_mode_read(adapter, + DP_DUAL_MODE_LSPCON_CURRENT_MODE, + &data, sizeof(data)); + if (!ret) + break; + } + if (ret < 0) { - DRM_ERROR("LSPCON read(0x80, 0x41) failed\n"); + DRM_DEBUG_KMS("LSPCON read(0x80, 0x41) failed\n"); return -EFAULT; } |