From: Fangzhi Zuo <Jerry.Zuo@xxxxxxx>
[why]
The first MST sideband message returns AUX_RET_ERROR_HPD_DISCON on
a certain Intel platform. Aux transaction is considered a failure if HPD
unexpectedly pulled low. The actual aux transaction success in such
case, hence do not return an error. Several Dell Intel-based Precision
systems had this issue, for example, Precision 3260 and 3460.
[how]
Not returning error when AUX_RET_ERROR_HPD_DISCON detected
on the first sideband message.
Cc: Harry Wentland <harry.wentland@xxxxxxx>
Cc: Mario Limonciello <mario.limonciello@xxxxxxx>
Cc: Qian Fu <Qian.Fu@xxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Fangzhi Zuo <Jerry.Zuo@xxxxxxx>
---
.../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 27 +++++++++++++++++++
.../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h | 8 ++++++
.../display/amdgpu_dm/amdgpu_dm_mst_types.c | 17 ++++++++++++
3 files changed, 52 insertions(+)
diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
index de1c139ae279..e0af3d003b5c 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -72,6 +72,7 @@
#include <linux/pci.h>
#include <linux/firmware.h>
#include <linux/component.h>
+#include <linux/dmi.h>
#include <drm/drm_atomic.h>
#include <drm/drm_atomic_uapi.h>
@@ -1400,6 +1401,29 @@ static bool dm_should_disable_stutter(struct pci_dev *pdev)
return false;
}
+static const struct dmi_system_id hpd_disconnect_quirk_table[] = {
+ {
+ .matches = {
+ DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
+ DMI_MATCH(DMI_PRODUCT_NAME, "Precision 3660"),
+ },
+ },
+ {}
+};
+
+void retrieve_dmi_info(struct amdgpu_display_manager *dm)
+{
+ const struct dmi_system_id *dmi_id;
+
+ dm->aux_hpd_discon_quirk = false;
+
+ dmi_id = dmi_first_match(hpd_disconnect_quirk_table);
+ if (dmi_id) {
+ dm->aux_hpd_discon_quirk = true;
+ DRM_INFO("aux_hpd_discon_quirk attached\n");
+ }
+}
+
static int amdgpu_dm_init(struct amdgpu_device *adev)
{
struct dc_init_data init_data;
@@ -1528,6 +1552,9 @@ static int amdgpu_dm_init(struct amdgpu_device *adev)
init_data.flags.enable_mipi_converter_optimization = true;
INIT_LIST_HEAD(&adev->dm.da_list);
+
+ retrieve_dmi_info(&adev->dm);
+
/* Display Core create. */
adev->dm.dc = dc_create(&init_data);
diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h
index e04e6b3f609f..33d66d4897dc 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h
@@ -547,6 +547,14 @@ struct amdgpu_display_manager {
* last successfully applied backlight values.
*/
u32 actual_brightness[AMDGPU_DM_MAX_NUM_EDP];
+
+ /**
+ * @aux_hpd_discon_quirk:
+ *
+ * quirk for hpd discon while aux is on-going.
+ * occurred on certain intel platform
+ */
+ bool aux_hpd_discon_quirk;
};
enum dsc_clock_force_state {
diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c
index 8237029cedf5..168d5676b657 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c
@@ -56,6 +56,8 @@ static ssize_t dm_dp_aux_transfer(struct drm_dp_aux *aux,
ssize_t result = 0;
struct aux_payload payload;
enum aux_return_code_type operation_result;
+ struct amdgpu_device *adev;
+ struct ddc_service *ddc;
if (WARN_ON(msg->size > 16))
return -E2BIG;
@@ -74,6 +76,21 @@ static ssize_t dm_dp_aux_transfer(struct drm_dp_aux *aux,
result = dc_link_aux_transfer_raw(TO_DM_AUX(aux)->ddc_service, &payload,
&operation_result);
+ /*
+ * w/a on certain intel platform where hpd is unexpected to pull low during
+ * 1st sideband message transaction by return AUX_RET_ERROR_HPD_DISCON
+ * aux transaction is succuess in such case, therefore bypass the error
+ */
+ ddc = TO_DM_AUX(aux)->ddc_service;
+ adev = ddc->ctx->driver_context;
+ if (adev->dm.aux_hpd_discon_quirk) {
+ if (msg->address == DP_SIDEBAND_MSG_DOWN_REQ_BASE &&
+ operation_result == AUX_RET_ERROR_HPD_DISCON) {
+ result = 0;
+ operation_result = AUX_RET_SUCCESS;
+ }
+ }
+
if (payload.write && result >= 0)
result = msg->size;
--
2.37.0
