[media] gscpa - sn9c20x: Add sd_isoc_init ensuring enough bw when i420 fmt
When using the SN9C20X_I420 fmt the sn9c20x needs more bandwidth
than our regular bandwidth calculations reserve.
This patch adds a sd_isoc_init function, which forces the use of a specific
altsetting when using the SN9C20X_I420 fmt.
This fixes the bottom 10-30% of the image getting corrupted when using
the SN9C20X_I420 fmt (which is the default fmt).
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Jean-François Moine <moinejf@free.fr>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/drivers/media/video/gspca/sn9c20x.c b/drivers/media/video/gspca/sn9c20x.c
index 7350718..b5fca91 100644
--- a/drivers/media/video/gspca/sn9c20x.c
+++ b/drivers/media/video/gspca/sn9c20x.c
@@ -2234,6 +2234,42 @@
}
}
+static int sd_isoc_init(struct gspca_dev *gspca_dev)
+{
+ struct usb_interface *intf;
+ u32 flags = gspca_dev->cam.cam_mode[(int)gspca_dev->curr_mode].priv;
+
+ /*
+ * When using the SN9C20X_I420 fmt the sn9c20x needs more bandwidth
+ * than our regular bandwidth calculations reserve, so we force the
+ * use of a specific altsetting when using the SN9C20X_I420 fmt.
+ */
+ if (!(flags & (MODE_RAW | MODE_JPEG))) {
+ intf = usb_ifnum_to_if(gspca_dev->dev, gspca_dev->iface);
+
+ if (intf->num_altsetting != 9) {
+ pr_warn("sn9c20x camera with unknown number of alt "
+ "settings (%d), please report!\n",
+ intf->num_altsetting);
+ gspca_dev->alt = intf->num_altsetting;
+ return 0;
+ }
+
+ switch (gspca_dev->width) {
+ case 160: /* 160x120 */
+ gspca_dev->alt = 2;
+ break;
+ case 320: /* 320x240 */
+ gspca_dev->alt = 6;
+ break;
+ default: /* >= 640x480 */
+ gspca_dev->alt = 9;
+ }
+ }
+
+ return 0;
+}
+
#define HW_WIN(mode, hstart, vstart) \
((const u8 []){hstart, 0, vstart, 0, \
(mode & MODE_SXGA ? 1280 >> 4 : 640 >> 4), \
@@ -2474,6 +2510,7 @@
.nctrls = ARRAY_SIZE(sd_ctrls),
.config = sd_config,
.init = sd_init,
+ .isoc_init = sd_isoc_init,
.start = sd_start,
.stopN = sd_stopN,
.pkt_scan = sd_pkt_scan,