Commit 61e57a8d authored by Adam Jackson's avatar Adam Jackson Committed by Dave Airlie
Browse files

drm/edid: Fix secondary block fetch. 



This makes fetching the second EDID block on HDMI monitors actually
work.  DDC can't transfer more than 128 bytes at a time.  Also,
rearrange the code so the pure DDC bits are separate from block parse.

Signed-off-by: default avatarAdam Jackson <ajax@redhat.com>
Signed-off-by: default avatarDave Airlie <airlied@redhat.com>
parent 95beb690

drivers/gpu/drm/drm_edid.c

+187 −143
Original line number Diff line number Diff line
@@ -2,6 +2,7 @@ 
 * Copyright (c) 2006 Luc Verhaegen (quirks list)

 * Copyright (c) 2007-2008 Intel Corporation

 *   Jesse Barnes <jesse.barnes@intel.com>

 * Copyright 2010 Red Hat, Inc.

 *

 * DDC probing routines (drm_ddc_read & drm_do_probe_ddc_edid) originally from

 * FB layer.
@@ -106,25 +107,25 @@ static struct edid_quirk { 
	{ "SAM", 638, EDID_QUIRK_PREFER_LARGE_60 },

};



/*** DDC fetch and block validation ***/



/* Valid EDID header has these bytes */

static const u8 edid_header[] = {

	0x00, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x00

};



/**

 * drm_edid_is_valid - sanity check EDID data

 * @edid: EDID data

 *

 * Sanity check the EDID block by looking at the header, the version number

 * and the checksum.  Return 0 if the EDID doesn't check out, or 1 if it's

 * valid.

/*

 * Sanity check the EDID block (base or extension).  Return 0 if the block

 * doesn't check out, or 1 if it's valid.

 */

bool drm_edid_is_valid(struct edid *edid)

static bool

drm_edid_block_valid(u8 *raw_edid)

{

	int i, score = 0;

	int i;

	u8 csum = 0;

	u8 *raw_edid = (u8 *)edid;

	struct edid *edid = (struct edid *)raw_edid;



	if (raw_edid[0] == 0x00) {

		int score = 0;



		for (i = 0; i < sizeof(edid_header); i++)

			if (raw_edid[i] == edid_header[i])
@@ -134,8 +135,10 @@ bool drm_edid_is_valid(struct edid *edid) 
		else if (score >= 6) {

			DRM_DEBUG("Fixing EDID header, your hardware may be failing\n");

			memcpy(raw_edid, edid_header, sizeof(edid_header));

	} else

		} else {

			goto bad;

		}

	}



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

		csum += raw_edid[i];
@@ -144,6 +147,9 @@ bool drm_edid_is_valid(struct edid *edid) 
		goto bad;

	}



	/* per-block-type checks */

	switch (raw_edid[0]) {

	case 0: /* base */

		if (edid->version != 1) {

			DRM_ERROR("EDID has major version %d, instead of 1\n", edid->version);

			goto bad;
@@ -151,6 +157,11 @@ bool drm_edid_is_valid(struct edid *edid) 


		if (edid->revision > 4)

			DRM_DEBUG("EDID minor > 4, assuming backward compatibility\n");

		break;



	default:

		break;

	}



	return 1;
@@ -162,8 +173,158 @@ bad: 
	}

	return 0;

}



/**

 * drm_edid_is_valid - sanity check EDID data

 * @edid: EDID data

 *

 * Sanity-check an entire EDID record (including extensions)

 */

bool drm_edid_is_valid(struct edid *edid)

{

	int i;

	u8 *raw = (u8 *)edid;



	if (!edid)

		return false;



	for (i = 0; i <= edid->extensions; i++)

		if (!drm_edid_block_valid(raw + i * EDID_LENGTH))

			return false;



	return true;

}

EXPORT_SYMBOL(drm_edid_is_valid);



#define DDC_ADDR 0x50

#define DDC_SEGMENT_ADDR 0x30

/**

 * Get EDID information via I2C.

 *

 * \param adapter : i2c device adaptor

 * \param buf     : EDID data buffer to be filled

 * \param len     : EDID data buffer length

 * \return 0 on success or -1 on failure.

 *

 * Try to fetch EDID information by calling i2c driver function.

 */

static int

drm_do_probe_ddc_edid(struct i2c_adapter *adapter, unsigned char *buf,

		      int block, int len)

{

	unsigned char start = block * EDID_LENGTH;

	struct i2c_msg msgs[] = {

		{

			.addr	= DDC_ADDR,

			.flags	= 0,

			.len	= 1,

			.buf	= &start,

		}, {

			.addr	= DDC_ADDR,

			.flags	= I2C_M_RD,

			.len	= len,

			.buf	= buf + start,

		}

	};



	if (i2c_transfer(adapter, msgs, 2) == 2)

		return 0;



	return -1;

}



static u8 *

drm_do_get_edid(struct drm_connector *connector, struct i2c_adapter *adapter)

{

	int i, j = 0;

	u8 *block, *new;



	if ((block = kmalloc(EDID_LENGTH, GFP_KERNEL)) == NULL)

		return NULL;



	/* base block fetch */

	for (i = 0; i < 4; i++) {

		if (drm_do_probe_ddc_edid(adapter, block, 0, EDID_LENGTH))

			goto out;

		if (drm_edid_block_valid(block))

			break;

	}

	if (i == 4)

		goto carp;



	/* if there's no extensions, we're done */

	if (block[0x7e] == 0)

		return block;



	new = krealloc(block, (block[0x7e] + 1) * EDID_LENGTH, GFP_KERNEL);

	if (!new)

		goto out;

	block = new;



	for (j = 1; j <= block[0x7e]; j++) {

		for (i = 0; i < 4; i++) {

			if (drm_do_probe_ddc_edid(adapter, block, j,

						  EDID_LENGTH))

				goto out;

			if (drm_edid_block_valid(block + j * EDID_LENGTH))

				break;

		}

		if (i == 4)

			goto carp;

	}



	return block;



carp:

	dev_warn(&connector->dev->pdev->dev, "%s: EDID block %d invalid.\n",

		 drm_get_connector_name(connector), j);



out:

	kfree(block);

	return NULL;

}



/**

 * Probe DDC presence.

 *

 * \param adapter : i2c device adaptor

 * \return 1 on success

 */

static bool

drm_probe_ddc(struct i2c_adapter *adapter)

{

	unsigned char out;



	return (drm_do_probe_ddc_edid(adapter, &out, 0, 1) == 0);

}



/**

 * drm_get_edid - get EDID data, if available

 * @connector: connector we're probing

 * @adapter: i2c adapter to use for DDC

 *

 * Poke the given i2c channel to grab EDID data if possible.  If found,

 * attach it to the connector.

 *

 * Return edid data or NULL if we couldn't find any.

 */

struct edid *drm_get_edid(struct drm_connector *connector,

			  struct i2c_adapter *adapter)

{

	struct edid *edid = NULL;



	if (drm_probe_ddc(adapter))

		edid = (struct edid *)drm_do_get_edid(connector, adapter);



	connector->display_info.raw_edid = (char *)edid;



	return edid;



}

EXPORT_SYMBOL(drm_get_edid);



/*** EDID parsing ***/



/**

 * edid_vendor - match a string against EDID's obfuscated vendor field

 * @edid: EDID to match
@@ -1141,123 +1302,6 @@ static int add_detailed_info_eedid(struct drm_connector *connector, 
	return modes;

}



#define DDC_ADDR 0x50

/**

 * Get EDID information via I2C.

 *

 * \param adapter : i2c device adaptor

 * \param buf     : EDID data buffer to be filled

 * \param len     : EDID data buffer length

 * \return 0 on success or -1 on failure.

 *

 * Try to fetch EDID information by calling i2c driver function.

 */

int drm_do_probe_ddc_edid(struct i2c_adapter *adapter,

			  unsigned char *buf, int len)

{

	unsigned char start = 0x0;

	struct i2c_msg msgs[] = {

		{

			.addr	= DDC_ADDR,

			.flags	= 0,

			.len	= 1,

			.buf	= &start,

		}, {

			.addr	= DDC_ADDR,

			.flags	= I2C_M_RD,

			.len	= len,

			.buf	= buf,

		}

	};



	if (i2c_transfer(adapter, msgs, 2) == 2)

		return 0;



	return -1;

}

EXPORT_SYMBOL(drm_do_probe_ddc_edid);



static int drm_ddc_read_edid(struct drm_connector *connector,

			     struct i2c_adapter *adapter,

			     char *buf, int len)

{

	int i;



	for (i = 0; i < 4; i++) {

		if (drm_do_probe_ddc_edid(adapter, buf, len))

			return -1;

		if (drm_edid_is_valid((struct edid *)buf))

			return 0;

	}



	/* repeated checksum failures; warn, but carry on */

	dev_warn(&connector->dev->pdev->dev, "%s: EDID invalid.\n",

		 drm_get_connector_name(connector));

	return -1;

}



/**

 * drm_get_edid - get EDID data, if available

 * @connector: connector we're probing

 * @adapter: i2c adapter to use for DDC

 *

 * Poke the given connector's i2c channel to grab EDID data if possible.

 *

 * Return edid data or NULL if we couldn't find any.

 */

struct edid *drm_get_edid(struct drm_connector *connector,

			  struct i2c_adapter *adapter)

{

	int ret;

	struct edid *edid;



	edid = kmalloc(EDID_LENGTH * (DRM_MAX_EDID_EXT_NUM + 1),

		       GFP_KERNEL);

	if (edid == NULL) {

		dev_warn(&connector->dev->pdev->dev,

			 "Failed to allocate EDID\n");

		goto end;

	}



	/* Read first EDID block */

	ret = drm_ddc_read_edid(connector, adapter,

				(unsigned char *)edid, EDID_LENGTH);

	if (ret != 0)

		goto clean_up;



	/* There are EDID extensions to be read */

	if (edid->extensions != 0) {

		int edid_ext_num = edid->extensions;



		if (edid_ext_num > DRM_MAX_EDID_EXT_NUM) {

			dev_warn(&connector->dev->pdev->dev,

				 "The number of extension(%d) is "

				 "over max (%d), actually read number (%d)\n",

				 edid_ext_num, DRM_MAX_EDID_EXT_NUM,

				 DRM_MAX_EDID_EXT_NUM);

			/* Reset EDID extension number to be read */

			edid_ext_num = DRM_MAX_EDID_EXT_NUM;

		}

		/* Read EDID including extensions too */

		ret = drm_ddc_read_edid(connector, adapter, (char *)edid,

					EDID_LENGTH * (edid_ext_num + 1));

		if (ret != 0)

			goto clean_up;



	}



	connector->display_info.raw_edid = (char *)edid;

	goto end;



clean_up:

	kfree(edid);

	edid = NULL;

end:

	return edid;



}

EXPORT_SYMBOL(drm_get_edid);



#define HDMI_IDENTIFIER 0x000C03

#define VENDOR_BLOCK    0x03

/**

include/drm/drm_crtc.h

+0 −2
Original line number Diff line number Diff line
@@ -666,8 +666,6 @@ extern void drm_fb_release(struct drm_file *file_priv); 
extern int drm_mode_group_init_legacy_group(struct drm_device *dev, struct drm_mode_group *group);

extern struct edid *drm_get_edid(struct drm_connector *connector,

				 struct i2c_adapter *adapter);

extern int drm_do_probe_ddc_edid(struct i2c_adapter *adapter,

				 unsigned char *buf, int len);

extern int drm_add_edid_modes(struct drm_connector *connector, struct edid *edid);

extern void drm_mode_probed_add(struct drm_connector *connector, struct drm_display_mode *mode);

extern void drm_mode_remove(struct drm_connector *connector, struct drm_display_mode *mode);

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