This is a note to let you know that I've just added the patch titled
drm/amd/display: Ignore First MST Sideband Message Return Error
to the 5.18-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
drm-amd-display-ignore-first-mst-sideband-message-re.patch
and it can be found in the queue-5.18 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit fbc814ab014f827e776915bb4fc58c66596c06ee
Author: Fangzhi Zuo <Jerry.Zuo@xxxxxxx>
Date: Wed Jul 6 15:52:46 2022 -0400
drm/amd/display: Ignore First MST Sideband Message Return Error
[ Upstream commit acea108fa067d140bd155161a79b1fcd967f4137 ]
[why]
First MST sideband message returns AUX_RET_ERROR_HPD_DISCON
on certain intel platform. Aux transaction considered failure
if HPD unexpected pulled low. The actual aux transaction success
in such case, hence do not return error.
[how]
Not returning error when AUX_RET_ERROR_HPD_DISCON detected
on the first sideband message.
v2: squash in additional DMI entries
v3: squash in static fix
Signed-off-by: Fangzhi Zuo <Jerry.Zuo@xxxxxxx>
Acked-by: Solomon Chiu <solomon.chiu@xxxxxxx>
Tested-by: Daniel Wheeler <daniel.wheeler@xxxxxxx>
Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
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 b55a433e829e..bfbd701a4c9a 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>
@@ -1391,6 +1392,41 @@ 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"),
+ },
+ },
+ {
+ .matches = {
+ DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
+ DMI_MATCH(DMI_PRODUCT_NAME, "Precision 3260"),
+ },
+ },
+ {
+ .matches = {
+ DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
+ DMI_MATCH(DMI_PRODUCT_NAME, "Precision 3460"),
+ },
+ },
+ {}
+};
+
+static 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;
@@ -1521,6 +1557,9 @@ static int amdgpu_dm_init(struct amdgpu_device *adev)
}
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 7e44b0429448..4844601a5f47 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h
@@ -546,6 +546,14 @@ 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 31ac1fce36f8..d864cae1af67 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
@@ -58,6 +58,8 @@ 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;
@@ -76,6 +78,21 @@ 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;
