From: Paul Elder paul.elder@ideasonboard.com
[ Upstream commit 89969a842e72b1b653140a4bbddd927b242736d0 ]
There is an issue where the host is unable to tell the gadget what frame rate it wants if the dwFrameIntervals in the interface descriptors are not in ascending order. This means that when instantiating a uvc gadget via configfs the user must make sure the dwFrameIntervals are in ascending order.
Instead of silently failing the breaking of this rule, we sort the dwFrameIntervals upon writing to configfs.
Signed-off-by: Paul Elder paul.elder@ideasonboard.com Reviewed-by: Laurent Pinchart laurent.pinchart@ideasonboard.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/usb/gadget/function/uvc_configfs.c | 13 +++++++++++++ 1 file changed, 13 insertions(+)
diff --git a/drivers/usb/gadget/function/uvc_configfs.c b/drivers/usb/gadget/function/uvc_configfs.c index 9478a7cdb1433..2e4c0391b5836 100644 --- a/drivers/usb/gadget/function/uvc_configfs.c +++ b/drivers/usb/gadget/function/uvc_configfs.c @@ -9,6 +9,9 @@ * * Author: Andrzej Pietrasiewicz andrzej.p@samsung.com */ + +#include <linux/sort.h> + #include "u_uvc.h" #include "uvc_configfs.h"
@@ -31,6 +34,14 @@ static struct configfs_attribute prefix##attr_##cname = { \ .show = prefix##cname##_show, \ }
+static int uvcg_config_compare_u32(const void *l, const void *r) +{ + u32 li = *(const u32 *)l; + u32 ri = *(const u32 *)r; + + return li < ri ? -1 : li == ri ? 0 : 1; +} + static inline struct f_uvc_opts *to_f_uvc_opts(struct config_item *item) { return container_of(to_config_group(item), struct f_uvc_opts, @@ -1134,6 +1145,8 @@ static ssize_t uvcg_frame_dw_frame_interval_store(struct config_item *item, kfree(ch->dw_frame_interval); ch->dw_frame_interval = frm_intrv; ch->frame.b_frame_interval_type = n; + sort(ch->dw_frame_interval, n, sizeof(*ch->dw_frame_interval), + uvcg_config_compare_u32, NULL); ret = len;
end: