With an unknown sensor, norm_maxw() and norm_maxh() return 0 as max. height and width values, which causes a devide by zero in size_to_scale(). Of course we could use speculative default values for unknown sensors, but the chance that the device works at this resolution without any driver/setup is very low and therefore not worth the efforts. Instead, just don't treat the device as camera. A message will then be printed to the log that the device isn't supported. Signed-off-by: Frank Schäfer <fschaefer.oss@xxxxxxxxxxxxxx> --- drivers/media/usb/em28xx/em28xx-cards.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/drivers/media/usb/em28xx/em28xx-cards.c b/drivers/media/usb/em28xx/em28xx-cards.c index 5f80a1b2fb8c..48c7fec47509 100644 --- a/drivers/media/usb/em28xx/em28xx-cards.c +++ b/drivers/media/usb/em28xx/em28xx-cards.c @@ -2917,7 +2917,9 @@ static void em28xx_card_setup(struct em28xx *dev) * If sensor is not found, then it isn't a webcam. */ if (dev->board.is_webcam) { - if (em28xx_detect_sensor(dev) < 0) + em28xx_detect_sensor(dev); + if (dev->em28xx_sensor == EM28XX_NOSENSOR) + /* NOTE: error/unknown sensor/no sensor */ dev->board.is_webcam = 0; } @@ -3665,9 +3667,11 @@ static int em28xx_usb_probe(struct usb_interface *interface, try_bulk = usb_xfer_mode > 0; } - /* Disable V4L2 if the device doesn't have a decoder */ + /* Disable V4L2 if the device doesn't have a decoder or image sensor */ if (has_video && - dev->board.decoder == EM28XX_NODECODER && !dev->board.is_webcam) { + dev->board.decoder == EM28XX_NODECODER && + dev->em28xx_sensor == EM28XX_NOSENSOR) { + dev_err(&interface->dev, "Currently, V4L2 is not supported on this model\n"); has_video = false; -- 2.12.2