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Commit 75c65ee2 authored by Robert Tarasov's avatar Robert Tarasov Committed by Alex Deucher
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drm/udl: Reading all edid blocks in DRM/UDL driver 



Now DRM/UDL driver retreives all edid data blocks instead of only base one.
Previous approch could lead to improper initialization of video mode with
certain monitors.

Signed-off-by: default avatarRobert Tarasov <tutankhamen@chromium.org>
Reviewed-by: default avatarAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: default avatarAlex Deucher <alexander.deucher@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171013001350.172155-2-tutankhamen@chromium.org
parent afdfc4c6

drivers/gpu/drm/udl/udl_connector.c

+68 −38
Original line number Diff line number Diff line
@@ -17,42 +17,79 @@ 
#include "udl_connector.h"

#include "udl_drv.h"



/* dummy connector to just get EDID,

   all UDL appear to have a DVI-D */



static u8 *udl_get_edid(struct udl_device *udl)

static bool udl_get_edid_block(struct udl_device *udl, int block_idx,

							   u8 *buff)

{

	u8 *block;

	char *rbuf;

	int ret, i;

	u8 *read_buff;



	block = kmalloc(EDID_LENGTH, GFP_KERNEL);

	if (block == NULL)

		return NULL;



	rbuf = kmalloc(2, GFP_KERNEL);

	if (rbuf == NULL)

		goto error;

	read_buff = kmalloc(2, GFP_KERNEL);

	if (!read_buff)

		return false;



	for (i = 0; i < EDID_LENGTH; i++) {

		int bval = (i + block_idx * EDID_LENGTH) << 8;

		ret = usb_control_msg(udl->udev,

				      usb_rcvctrlpipe(udl->udev, 0), (0x02),

				      (0x80 | (0x02 << 5)), i << 8, 0xA1, rbuf, 2,

				      HZ);

				      usb_rcvctrlpipe(udl->udev, 0),

					  (0x02), (0x80 | (0x02 << 5)), bval,

					  0xA1, read_buff, 2, HZ);

		if (ret < 1) {

			DRM_ERROR("Read EDID byte %d failed err %x\n", i, ret);

			goto error;

			kfree(read_buff);

			return false;

		}

		block[i] = rbuf[1];

		buff[i] = read_buff[1];

	}



	kfree(rbuf);

	return block;

	kfree(read_buff);

	return true;

}



error:

	kfree(block);

	kfree(rbuf);

	return NULL;

static bool udl_get_edid(struct udl_device *udl, u8 **result_buff,

			 int *result_buff_size)

{

	int i, extensions;

	u8 *block_buff = NULL, *buff_ptr;



	block_buff = kmalloc(EDID_LENGTH, GFP_KERNEL);

	if (block_buff == NULL)

		return false;



	if (udl_get_edid_block(udl, 0, block_buff) &&

	    memchr_inv(block_buff, 0, EDID_LENGTH)) {

		extensions = ((struct edid *)block_buff)->extensions;

		if (extensions > 0) {

			/* we have to read all extensions one by one */

			*result_buff_size = EDID_LENGTH * (extensions + 1);

			*result_buff = kmalloc(*result_buff_size, GFP_KERNEL);

			buff_ptr = *result_buff;

			if (buff_ptr == NULL) {

				kfree(block_buff);

				return false;

			}

			memcpy(buff_ptr, block_buff, EDID_LENGTH);

			kfree(block_buff);

			buff_ptr += EDID_LENGTH;

			for (i = 1; i < extensions; ++i) {

				if (udl_get_edid_block(udl, i, buff_ptr)) {

					buff_ptr += EDID_LENGTH;

				} else {

					kfree(*result_buff);

					*result_buff = NULL;

					return false;

				}

			}

			return true;

		}

		/* we have only base edid block */

		*result_buff = block_buff;

		*result_buff_size = EDID_LENGTH;

		return true;

	}



	kfree(block_buff);



	return false;

}



static int udl_get_modes(struct drm_connector *connector)
@@ -84,32 +121,25 @@ static int udl_mode_valid(struct drm_connector *connector, 
static enum drm_connector_status

udl_detect(struct drm_connector *connector, bool force)

{

	struct edid *edid;

	u8 *edid_buff = NULL;

	int edid_buff_size = 0;

	struct udl_device *udl = connector->dev->dev_private;

	struct udl_drm_connector *udl_connector =

					container_of(connector,

					struct udl_drm_connector,

					connector);



	/* cleanup previous edid */

	if (udl_connector->edid != NULL) {

		kfree(udl_connector->edid);

		udl_connector->edid = NULL;

	}



	edid = (struct edid *)udl_get_edid(udl);

	if (!edid || !memchr_inv(edid, 0, EDID_LENGTH))

		return connector_status_disconnected;



	udl_connector->edid = edid;

	if (!udl_get_edid(udl, &edid_buff, &edid_buff_size))

		return connector_status_disconnected;



	/*

	 * We only read the main block, but if the monitor reports extension

	 * blocks then the drm edid code expects them to be present, so patch

	 * the extension count to 0.

	 */

	udl_connector->edid->checksum +=

			udl_connector->edid->extensions;

	udl_connector->edid->extensions = 0;

	udl_connector->edid = (struct edid *)edid_buff;

	

	return connector_status_connected;

}