Commit 8ef8cc4f authored by Bernie Thompson's avatar Bernie Thompson Committed by Greg Kroah-Hartman
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staging: udlfb: support for writing backup EDID to sysfs file 



Support writing default/backup edid via /sys/class/graphics/fb?/edid

Writing a backup edid blob to the 'edid' file will cause udlfb to
attempt to re-read the edid from hardware.
If we still don't have a good edid, it will use the backup edid instead.
The intent is to 1) enable user-supplied edid
2) enable udev rules to backup the last known good edid
for a device, and then provide that edid as a backup for all future starts

Signed-off-by: default avatarBernie Thompson <bernie@plugable.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 1572f91c

drivers/staging/udlfb/udlfb.c

+26 −2
Original line number Diff line number Diff line
@@ -1306,6 +1306,29 @@ static ssize_t edid_show( 
	return count;

}



static ssize_t edid_store(

			struct file *filp,

			struct kobject *kobj, struct bin_attribute *a,

			char *src, loff_t src_off, size_t src_size) {

	struct device *fbdev = container_of(kobj, struct device, kobj);

	struct fb_info *fb_info = dev_get_drvdata(fbdev);

	struct dlfb_data *dev = fb_info->par;



	/* We only support write of entire EDID at once, no offset*/

	if ((src_size < MIN_EDID_SIZE) ||

	    (src_size > MAX_EDID_SIZE) ||

	    (src_off != 0))

		return 0;



	dlfb_setup_modes(dev, fb_info, src, src_size);



	if (dev->edid && (memcmp(src, dev->edid, src_size) == 0)) {

		dl_info("sysfs written EDID is new default\n");

		dlfb_ops_set_par(fb_info);

		return src_size;

	} else

		return 0;

}



static ssize_t metrics_reset_store(struct device *fbdev,

			   struct device_attribute *attr,
@@ -1348,9 +1371,10 @@ static ssize_t use_defio_store(struct device *fbdev, 


static struct bin_attribute edid_attr = {

	.attr.name = "edid",

	.attr.mode = 0444,

	.size = 128,

	.attr.mode = 0666,

	.size = MAX_EDID_SIZE,

	.read = edid_show,

	.write = edid_store

};



static struct device_attribute fb_device_attrs[] = {