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Commit 4cf2b281 authored by Thomas Wood's avatar Thomas Wood Committed by Daniel Vetter
Browse files

drm/debugfs: add an "edid_override" file per connector 



Add a file to debugfs for each connector to allow the EDID to be
overridden.

v2: Copy ubuf before accessing it and reject invalid length data. (David
    Herrmann)
    Ensure override_edid is reset when a new EDID value is written.
    (David Herrmann)
    Fix the debugfs file permissions. (David Herrmann)

Signed-off-by: default avatarThomas Wood <thomas.wood@intel.com>
Reviewed-by: default avatarAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
parent 30f65707

drivers/gpu/drm/drm_crtc.c

+4 −0
Original line number Diff line number Diff line
@@ -3763,6 +3763,10 @@ int drm_mode_connector_update_edid_property(struct drm_connector *connector, 
	struct drm_device *dev = connector->dev;

	int ret, size;



	/* ignore requests to set edid when overridden */

	if (connector->override_edid)

		return 0;



	if (connector->edid_blob_ptr)

		drm_property_destroy_blob(dev, connector->edid_blob_ptr);

drivers/gpu/drm/drm_debugfs.c

+68 −0
Original line number Diff line number Diff line
@@ -35,6 +35,7 @@ 
#include <linux/slab.h>

#include <linux/export.h>

#include <drm/drmP.h>

#include <drm/drm_edid.h>



#if defined(CONFIG_DEBUG_FS)
@@ -304,6 +305,67 @@ static ssize_t connector_write(struct file *file, const char __user *ubuf, 
	return len;

}



static int edid_show(struct seq_file *m, void *data)

{

	struct drm_connector *connector = m->private;

	struct drm_property_blob *edid = connector->edid_blob_ptr;



	if (connector->override_edid && edid)

		seq_write(m, edid->data, edid->length);



	return 0;

}



static int edid_open(struct inode *inode, struct file *file)

{

	struct drm_connector *dev = inode->i_private;



	return single_open(file, edid_show, dev);

}



static ssize_t edid_write(struct file *file, const char __user *ubuf,

			  size_t len, loff_t *offp)

{

	struct seq_file *m = file->private_data;

	struct drm_connector *connector = m->private;

	char *buf;

	struct edid *edid;

	int ret;



	buf = memdup_user(ubuf, len);

	if (IS_ERR(buf))

		return PTR_ERR(buf);



	edid = (struct edid *) buf;



	if (len == 5 && !strncmp(buf, "reset", 5)) {

		connector->override_edid = false;

		ret = drm_mode_connector_update_edid_property(connector, NULL);

	} else if (len < EDID_LENGTH ||

		   EDID_LENGTH * (1 + edid->extensions) > len)

		ret = -EINVAL;

	else {

		connector->override_edid = false;

		ret = drm_mode_connector_update_edid_property(connector, edid);

		if (!ret)

			connector->override_edid = true;

	}



	kfree(buf);



	return (ret) ? ret : len;

}



static const struct file_operations drm_edid_fops = {

	.owner = THIS_MODULE,

	.open = edid_open,

	.read = seq_read,

	.llseek = seq_lseek,

	.release = single_release,

	.write = edid_write

};





static const struct file_operations drm_connector_fops = {

	.owner = THIS_MODULE,

	.open = connector_open,
@@ -333,6 +395,12 @@ int drm_debugfs_connector_add(struct drm_connector *connector) 
	if (!ent)

		goto error;



	/* edid */

	ent = debugfs_create_file("edid_override", S_IRUGO | S_IWUSR, root,

				  connector, &drm_edid_fops);

	if (!ent)

		goto error;



	return 0;



error:

drivers/gpu/drm/drm_probe_helper.c

+8 −1
Original line number Diff line number Diff line
@@ -130,7 +130,14 @@ static int drm_helper_probe_single_connector_modes_merge_bits(struct drm_connect 
	count = drm_load_edid_firmware(connector);

	if (count == 0)

#endif

	{

		if (connector->override_edid) {

			struct edid *edid = (struct edid *) connector->edid_blob_ptr->data;



			count = drm_add_edid_modes(connector, edid);

		} else

			count = (*connector_funcs->get_modes)(connector);

	}



	if (count == 0 && connector->status == connector_status_connected)

		count = drm_add_modes_noedid(connector, 1024, 768);

include/drm/drm_crtc.h

+1 −0
Original line number Diff line number Diff line
@@ -533,6 +533,7 @@ struct drm_connector { 


	/* forced on connector */

	enum drm_connector_force force;

	bool override_edid;

	uint32_t encoder_ids[DRM_CONNECTOR_MAX_ENCODER];

	struct drm_encoder *encoder; /* currently active encoder */