diff options
Diffstat (limited to 'drivers/gpu/drm/drm_dp_helper.c')
| -rw-r--r-- | drivers/gpu/drm/drm_dp_helper.c | 46 |
1 files changed, 44 insertions, 2 deletions
diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c index 8f11b8741e42..5d20255f3db3 100644 --- a/drivers/gpu/drm/drm_dp_helper.c +++ b/drivers/gpu/drm/drm_dp_helper.c @@ -223,7 +223,7 @@ static int drm_dp_dpcd_access(struct drm_dp_aux *aux, u8 request, err = ret; } - DRM_DEBUG_KMS("too many retries, giving up\n"); + DRM_DEBUG_KMS("Too many retries, giving up. First error: %d\n", err); ret = err; unlock: @@ -574,7 +574,17 @@ static int drm_dp_i2c_do_msg(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg) if (ret == -EBUSY) continue; - DRM_DEBUG_KMS("transaction failed: %d\n", ret); + /* + * While timeouts can be errors, they're usually normal + * behavior (for instance, when a driver tries to + * communicate with a non-existant DisplayPort device). + * Avoid spamming the kernel log with timeout errors. + */ + if (ret == -ETIMEDOUT) + DRM_DEBUG_KMS_RATELIMITED("transaction timed out\n"); + else + DRM_DEBUG_KMS("transaction failed: %d\n", ret); + return ret; } @@ -860,3 +870,35 @@ void drm_dp_aux_unregister(struct drm_dp_aux *aux) i2c_del_adapter(&aux->ddc); } EXPORT_SYMBOL(drm_dp_aux_unregister); + +#define PSR_SETUP_TIME(x) [DP_PSR_SETUP_TIME_ ## x >> DP_PSR_SETUP_TIME_SHIFT] = (x) + +/** + * drm_dp_psr_setup_time() - PSR setup in time usec + * @psr_cap: PSR capabilities from DPCD + * + * Returns: + * PSR setup time for the panel in microseconds, negative + * error code on failure. + */ +int drm_dp_psr_setup_time(const u8 psr_cap[EDP_PSR_RECEIVER_CAP_SIZE]) +{ + static const u16 psr_setup_time_us[] = { + PSR_SETUP_TIME(330), + PSR_SETUP_TIME(275), + PSR_SETUP_TIME(165), + PSR_SETUP_TIME(110), + PSR_SETUP_TIME(55), + PSR_SETUP_TIME(0), + }; + int i; + + i = (psr_cap[1] & DP_PSR_SETUP_TIME_MASK) >> DP_PSR_SETUP_TIME_SHIFT; + if (i >= ARRAY_SIZE(psr_setup_time_us)) + return -EINVAL; + + return psr_setup_time_us[i]; +} +EXPORT_SYMBOL(drm_dp_psr_setup_time); + +#undef PSR_SETUP_TIME |