usb: gadget: uvc: Fix string descriptor STALL issue when multiple uvc functions are added to a configuration
This patch solved the string descriptor STALL issue when we add multiple UVC
functions in a single configuration using a 'webcam.c' like composite driver.
Signed-off-by: Bhupesh Sharma <bhupesh.sharma@st.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
diff --git a/drivers/usb/gadget/f_uvc.c b/drivers/usb/gadget/f_uvc.c
index 2022fe49..054c35a 100644
--- a/drivers/usb/gadget/f_uvc.c
+++ b/drivers/usb/gadget/f_uvc.c
@@ -619,22 +619,28 @@
uvc->desc.fs_streaming = fs_streaming;
uvc->desc.hs_streaming = hs_streaming;
- /* Allocate string descriptor numbers. */
- if ((ret = usb_string_id(c->cdev)) < 0)
- goto error;
- uvc_en_us_strings[UVC_STRING_ASSOCIATION_IDX].id = ret;
- uvc_iad.iFunction = ret;
+ /* maybe allocate device-global string IDs, and patch descriptors */
+ if (uvc_en_us_strings[UVC_STRING_ASSOCIATION_IDX].id == 0) {
+ /* Allocate string descriptor numbers. */
+ ret = usb_string_id(c->cdev);
+ if (ret < 0)
+ goto error;
+ uvc_en_us_strings[UVC_STRING_ASSOCIATION_IDX].id = ret;
+ uvc_iad.iFunction = ret;
- if ((ret = usb_string_id(c->cdev)) < 0)
- goto error;
- uvc_en_us_strings[UVC_STRING_CONTROL_IDX].id = ret;
- uvc_control_intf.iInterface = ret;
+ ret = usb_string_id(c->cdev);
+ if (ret < 0)
+ goto error;
+ uvc_en_us_strings[UVC_STRING_CONTROL_IDX].id = ret;
+ uvc_control_intf.iInterface = ret;
- if ((ret = usb_string_id(c->cdev)) < 0)
- goto error;
- uvc_en_us_strings[UVC_STRING_STREAMING_IDX].id = ret;
- uvc_streaming_intf_alt0.iInterface = ret;
- uvc_streaming_intf_alt1.iInterface = ret;
+ ret = usb_string_id(c->cdev);
+ if (ret < 0)
+ goto error;
+ uvc_en_us_strings[UVC_STRING_STREAMING_IDX].id = ret;
+ uvc_streaming_intf_alt0.iInterface = ret;
+ uvc_streaming_intf_alt1.iInterface = ret;
+ }
/* Register the function. */
uvc->func.name = "uvc";