[PATCH 4.9 110/177] video: udlfb: Fix read EDID timeout

From: Greg Kroah-Hartman
Date: Mon Dec 18 2017 - 11:02:57 EST


4.9-stable review patch. If anyone has any objections, please let me know.

------------------

From: Ladislav Michl <ladis@xxxxxxxxxxxxxx>


[ Upstream commit c98769475575c8a585f5b3952f4b5f90266f699b ]

While usb_control_msg function expects timeout in miliseconds, a value
of HZ is used. Replace it with USB_CTRL_GET_TIMEOUT and also fix error
message which looks like:
udlfb: Read EDID byte 78 failed err ffffff92
as error is either negative errno or number of bytes transferred use %d
format specifier.

Returned EDID is in second byte, so return error when less than two bytes
are received.

Fixes: 18dffdf8913a ("staging: udlfb: enhance EDID and mode handling support")
Signed-off-by: Ladislav Michl <ladis@xxxxxxxxxxxxxx>
Cc: Bernie Thompson <bernie@xxxxxxxxxxxx>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@xxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/video/fbdev/udlfb.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)

--- a/drivers/video/fbdev/udlfb.c
+++ b/drivers/video/fbdev/udlfb.c
@@ -769,11 +769,11 @@ static int dlfb_get_edid(struct dlfb_dat

for (i = 0; i < len; i++) {
ret = usb_control_msg(dev->udev,
- usb_rcvctrlpipe(dev->udev, 0), (0x02),
- (0x80 | (0x02 << 5)), i << 8, 0xA1, rbuf, 2,
- HZ);
- if (ret < 1) {
- pr_err("Read EDID byte %d failed err %x\n", i, ret);
+ usb_rcvctrlpipe(dev->udev, 0), 0x02,
+ (0x80 | (0x02 << 5)), i << 8, 0xA1,
+ rbuf, 2, USB_CTRL_GET_TIMEOUT);
+ if (ret < 2) {
+ pr_err("Read EDID byte %d failed: %d\n", i, ret);
i--;
break;
}