Commit acea108f authored by Fangzhi Zuo's avatar Fangzhi Zuo Committed by Alex Deucher
Browse files

drm/amd/display: Ignore First MST Sideband Message Return Error 



[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: default avatarFangzhi Zuo <Jerry.Zuo@amd.com>
Acked-by: default avatarSolomon Chiu <solomon.chiu@amd.com>
Tested-by: default avatarDaniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: default avatarAlex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
parent 3590b44b

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c

+39 −0
Original line number Diff line number Diff line
@@ -72,6 +72,7 @@ 
#include <linux/pci.h>

#include <linux/firmware.h>

#include <linux/component.h>

#include <linux/dmi.h>



#include <drm/display/drm_dp_mst_helper.h>

#include <drm/display/drm_hdmi_helper.h>
@@ -1382,6 +1383,41 @@ 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;
@@ -1508,6 +1544,9 @@ 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);

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h

+8 −0
Original line number Diff line number Diff line
@@ -540,6 +540,14 @@ 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 {

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c

+17 −0
Original line number Diff line number Diff line
@@ -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;