>From the CI builds, its been observed that during a driver reload/insert, dp dual mode read function sometimes fails to read from dual mode devices (like LSPCON) 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. Cc: Ville Syrjala <ville.syrjala@xxxxxxxxxxxxxxx> Cc: Imre Deak <imre.deak@xxxxxxxxx> Signed-off-by: Shashank Sharma <shashank.sharma@xxxxxxxxx> --- drivers/gpu/drm/drm_dp_dual_mode_helper.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/drm_dp_dual_mode_helper.c b/drivers/gpu/drm/drm_dp_dual_mode_helper.c index 80e62f6..13f67a36 100644 --- a/drivers/gpu/drm/drm_dp_dual_mode_helper.c +++ b/drivers/gpu/drm/drm_dp_dual_mode_helper.c @@ -75,8 +75,15 @@ ssize_t drm_dp_dual_mode_read(struct i2c_adapter *adapter, }, }; int ret; + int retry; + + for (retry = 5; ; ) { + ret = i2c_transfer(adapter, msgs, ARRAY_SIZE(msgs)); + if (ret > 0 || !retry--) + break; + usleep_range(500, 1000); + } - ret = i2c_transfer(adapter, msgs, ARRAY_SIZE(msgs)); if (ret < 0) return ret; if (ret != ARRAY_SIZE(msgs)) @@ -420,7 +427,7 @@ int drm_lspcon_get_mode(struct i2c_adapter *adapter, ret = drm_dp_dual_mode_read(adapter, DP_DUAL_MODE_LSPCON_CURRENT_MODE, &data, sizeof(data)); if (ret < 0) { - DRM_ERROR("LSPCON read(0x80, 0x41) failed\n"); + DRM_DEBUG_KMS("LSPCON read(0x80, 0x41) failed\n"); return -EFAULT; } -- 2.7.4 _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx