diff options
Diffstat (limited to 'drivers/gpu/drm/i915/intel_sdvo.c')
| -rw-r--r-- | drivers/gpu/drm/i915/intel_sdvo.c | 31 |
1 files changed, 19 insertions, 12 deletions
diff --git a/drivers/gpu/drm/i915/intel_sdvo.c b/drivers/gpu/drm/i915/intel_sdvo.c index a4bee83df74..0e03985b0fe 100644 --- a/drivers/gpu/drm/i915/intel_sdvo.c +++ b/drivers/gpu/drm/i915/intel_sdvo.c @@ -509,7 +509,7 @@ out: static bool intel_sdvo_read_response(struct intel_sdvo *intel_sdvo, void *response, int response_len) { - u8 retry = 5; + u8 retry = 15; /* 5 quick checks, followed by 10 long checks */ u8 status; int i; @@ -522,14 +522,27 @@ static bool intel_sdvo_read_response(struct intel_sdvo *intel_sdvo, * command to be complete. * * Check 5 times in case the hardware failed to read the docs. + * + * Also beware that the first response by many devices is to + * reply PENDING and stall for time. TVs are notorious for + * requiring longer than specified to complete their replies. + * Originally (in the DDX long ago), the delay was only ever 15ms + * with an additional delay of 30ms applied for TVs added later after + * many experiments. To accommodate both sets of delays, we do a + * sequence of slow checks if the device is falling behind and fails + * to reply within 5*15µs. */ if (!intel_sdvo_read_byte(intel_sdvo, SDVO_I2C_CMD_STATUS, &status)) goto log_fail; - while (status == SDVO_CMD_STATUS_PENDING && retry--) { - udelay(15); + while (status == SDVO_CMD_STATUS_PENDING && --retry) { + if (retry < 10) + msleep(15); + else + udelay(15); + if (!intel_sdvo_read_byte(intel_sdvo, SDVO_I2C_CMD_STATUS, &status)) @@ -1535,15 +1548,9 @@ intel_sdvo_detect(struct drm_connector *connector, bool force) struct intel_sdvo_connector *intel_sdvo_connector = to_intel_sdvo_connector(connector); enum drm_connector_status ret; - if (!intel_sdvo_write_cmd(intel_sdvo, - SDVO_CMD_GET_ATTACHED_DISPLAYS, NULL, 0)) - return connector_status_unknown; - - /* add 30ms delay when the output type might be TV */ - if (intel_sdvo->caps.output_flags & SDVO_TV_MASK) - msleep(30); - - if (!intel_sdvo_read_response(intel_sdvo, &response, 2)) + if (!intel_sdvo_get_value(intel_sdvo, + SDVO_CMD_GET_ATTACHED_DISPLAYS, + &response, 2)) return connector_status_unknown; DRM_DEBUG_KMS("SDVO response %d %d [%x]\n", |