drm/i915: Add check for corrupt raw EDID header for Displayport compliance testing
Subsystems (3)
A message that is not in the archive (sent off-list or not yet received): [email protected]
PATCH 4/9 drm/i915: Add check for corrupt raw EDID header for Displayport compliance testing
Displayport compliance test 4.2.2.6 requires that a source device be capable of detecting a corrupt EDID. To do this, the test sets up an invalid EDID header to be read by the source device. Unfortunately, the DRM EDID reading and parsing functions are actually too good in this case and prevent the source from reading the corrupted EDID. The result is a failed compliance test.
In order to successfully pass the test, the raw EDID header must be checked on each read to see if has been "corrupted". If an invalid raw header is detected, a flag is set that allows the compliance testing code to acknowledge that fact and react appropriately. The flag is automatically cleared on read.
This code is designed to expressly work for compliance testing without disrupting normal operations for EDID reading and parsing.
--- drivers/gpu/drm/drm_edid.c | 33 +++++++++++++++++++++++++++++++++ drivers/gpu/drm/i915/intel_dp.c | 17 +++++++++++++++++ drivers/gpu/drm/i915/intel_drv.h | 1 + include/drm/drm_edid.h | 5 +++++ 4 files changed, 56 insertions(+)
drivers/gpu/drm/drm_edid.c +33 -0
@@ -990,6 +990,32 @@ static const u8 edid_header[] = { 0x00, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x00 }; + +/* Flag for EDID corruption testing +* Displayport Link CTS Core 1.2 rev1.1 - 4.2.2.6 +*/ +static bool raw_edid_header_corrupted; + +/** +* drm_raw_edid_header_valid - check to see if the raw header is +* corrupt or not. Used solely for Displayport compliance +* testing and required by Link CTS Core 1.2 rev1.1 4.2.2.6. +* @raw_edid: pointer to raw base EDID block +* +* Indicates whether the original EDID header as read from the +* device was corrupt or not. Clears on read. +* +* Return: true if the raw header was corrupt, otherwise false +*/ +bool drm_raw_edid_header_corrupt (void ) +{ +bool corrupted = raw_edid_header_corrupted; + + raw_edid_header_corrupted =0 ; +return corrupted; +} +EXPORT_SYMBOL (drm_raw_edid_header_corrupt); +/** * drm_edid_header_is_valid - sanity check the header of the base EDID block * @raw_edid: pointer to raw base EDID block
@@ -1006,6 +1032,13 @@ int drm_edid_header_is_valid(const u8 *raw_edid)if (raw_edid[i] == edid_header[i]) score++; +if (score !=8 ) { +/* Log and set flag here for EDID corruption testing +* Displayport Link CTS Core 1.2 rev1.1 - 4.2.2.6 +*/ +DRM_DEBUG_DRIVER ("Raw EDID header invalid\n" ); + raw_edid_header_corrupted =1 ; + }return score; }EXPORT_SYMBOL (drm_edid_header_is_valid);
drivers/gpu/drm/i915/intel_dp.c +17 -0
@@ -3824,6 +3824,9 @@ update_status: &response, 1);if (status <=0 )DRM_DEBUG_KMS ("Could not write test response to sink\n" ); + +/* Clear flag here, after testing is complete*/ + intel_dp->compliance_edid_invalid =0 ; } static int
@@ -3896,6 +3899,10 @@ intel_dp_check_link_status(struct intel_dp *intel_dp) {struct drm_device *dev =intel_dp_to_dev (intel_dp);struct intel_encoder *intel_encoder = &dp_to_dig_port (intel_dp)->base; +struct drm_connector *connector = &intel_dp->attached_connector->base; +struct i2c_adapter *adapter = &intel_dp->aux.ddc; +struct edid *edid_read =NULL ; +u8 sink_irq_vector;u8 link_status[DP_LINK_STATUS_SIZE ];
@@ -3912,6 +3919,16 @@ intel_dp_check_link_status(struct intel_dp *intel_dp)return ; } +/* Compliance testing requires an EDID read for all HPD events +* Link CTS Core 1.2 rev 1.1: Test 4.2.2.1 +* Flag set here will be handled in the EDID test function +*/ + edid_read =drm_get_edid (connector, adapter); +if (!edid_read ||drm_raw_edid_header_corrupt () ==1 ) { +DRM_DEBUG_DRIVER ("EDID invalid, setting flag\n" ); + intel_dp->compliance_edid_invalid =1 ; + } +/* Try to read the source of the interrupt */ if (intel_dp->dpcd[DP_DPCD_REV ] >=0x11 &&intel_dp_get_sink_irq (intel_dp, &sink_irq_vector)) {
drivers/gpu/drm/i915/intel_drv.h +1 -0
@@ -651,6 +651,7 @@ struct intel_dp {/* Displayport compliance testing */ unsigned long compliance_test_type;bool compliance_testing_active; +bool compliance_edid_invalid; };struct intel_digital_port {
include/drm/drm_edid.h +5 -0
@@ -388,4 +388,9 @@ struct edid *drm_do_get_edid(struct drm_connector *connector, size_t len), void *data); +/* Check for corruption in raw EDID header - Displayport compliance +* Displayport Link CTS Core 1.2 rev1.1 - 4.2.2.6 +*/ +bool drm_raw_edid_header_corrupt (void ); +#endif /* __DRM_EDID_H__ */
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1.9.1 _______________________________________________ dri-devel mailing list [email protected] http://lists.freedesktop.org/mailman/listinfo/dri-devel
PATCH 7/9 drm/i915: Fix for DP CTS test 4.2.2.5 - I2C DEFER handling
In reply to a message not in the archiveFor test 4.2.2.5 to pass per the Link CTS Core 1.2 rev1.1 spec, the source device must attempt at least 7 times to read the EDID when it receives an I2C defer. The normal DRM code makes only 7 retries, regardless of whether or not the response is a native defer or an I2C defer. Test 4.2.2.5 fails since there are native defers interspersed with the I2C defers which results in less than 7 EDID read attempts.
The solution is to decrement the retry counter when an I2C DEFER is returned such that another read attempt will be made. This situation should normally only occur in compliance testing, however, as a worse case real-world scenario, it would result in 13 attempts ( 6 native defers, 7 I2C defers) for a single transaction to complete. The net result is a slightly slower response to an EDID read that shouldn't significantly impact overall performance.
--- drivers/gpu/drm/drm_dp_helper.c | 5 +++++ 1 file changed, 5 insertions(+)
drivers/gpu/drm/drm_dp_helper.c +5 -0
@@ -469,6 +469,11 @@ static int drm_dp_i2c_do_msg(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg)case DP_AUX_I2C_REPLY_DEFER :DRM_DEBUG_KMS ("I2C defer\n" ); aux->i2c_defer_count++; +/* DP Compliance Test 4.2.2.5 Requirement: +* Must have at least 7 retries for I2C defers on the +* transaction to pass this test +*/ + retry--;usleep_range (400 ,500 );continue ;
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1.9.1 _______________________________________________ dri-devel mailing list [email protected] http://lists.freedesktop.org/mailman/listinfo/dri-devel
PATCH 9/9 drm: Fix the 'native defer' message in drm_dp_i2c_do_msg()
In reply to a message not in the archiveThe debug message is missing a newline at the end and it makes the logs hard to read when a device defers a lot. Simple 2-character fix adds the newline at the end.
--- drivers/gpu/drm/drm_dp_helper.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
drivers/gpu/drm/drm_dp_helper.c +1 -1
@@ -433,7 +433,7 @@ static int drm_dp_i2c_do_msg(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg)return -EREMOTEIO ;case DP_AUX_NATIVE_REPLY_DEFER : -DRM_DEBUG_KMS ("native defer" ); +DRM_DEBUG_KMS ("native defer\n" );/* * We could check for I2C bit rate capabilities and if * available adjust this interval. We could also be
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1.9.1 _______________________________________________ dri-devel mailing list [email protected] http://lists.freedesktop.org/mailman/listinfo/dri-devel