We have historic problem that the gadget will not work if the gadget is build-in and the udc driver is defered probe due to some resources are not ready. Below links are related to this problem.
http://marc.info/?l=linux-usb&m=139380872501745&w=2 http://marc.info/?l=linux-usb&m=137991612311893&w=2 http://marc.info/?l=linux-usb&m=137706435611447&w=2 This patch saves pointer of usb_gadget_driver when the udc is not ready, and redo usb_gadget_probe_driver when the udc is ready This method may not be good enough, but we need to find a way to fix this problem, so I post this RFC to see if to see comments, someone may have a better solution:) Signed-off-by: Peter Chen <peter.c...@freescale.com> --- drivers/usb/gadget/udc-core.c | 15 +++++++++++++-- 1 files changed, 13 insertions(+), 2 deletions(-) diff --git a/drivers/usb/gadget/udc-core.c b/drivers/usb/gadget/udc-core.c index 27768a7..1b991ef 100644 --- a/drivers/usb/gadget/udc-core.c +++ b/drivers/usb/gadget/udc-core.c @@ -48,6 +48,11 @@ struct usb_udc { static struct class *udc_class; static LIST_HEAD(udc_list); static DEFINE_MUTEX(udc_lock); +/* + * Only used for saving usb_gadget_driver pointer + * when the udc is not ready + */ +struct usb_gadget_driver *saved_gadget_driver; /* ------------------------------------------------------------------------- */ @@ -272,7 +277,12 @@ EXPORT_SYMBOL_GPL(usb_add_gadget_udc_release); */ int usb_add_gadget_udc(struct device *parent, struct usb_gadget *gadget) { - return usb_add_gadget_udc_release(parent, gadget, NULL); + int ret = usb_add_gadget_udc_release(parent, gadget, NULL); + if (!ret && saved_gadget_driver) { + usb_gadget_probe_driver(saved_gadget_driver); + saved_gadget_driver = NULL; + } + return ret; } EXPORT_SYMBOL_GPL(usb_add_gadget_udc); @@ -406,7 +416,8 @@ int usb_gadget_probe_driver(struct usb_gadget_driver *driver) goto found; } - pr_debug("couldn't find an available UDC\n"); + pr_debug("couldn't find an UDC, retry probe when udc is ready\n"); + saved_gadget_driver = driver; mutex_unlock(&udc_lock); return -ENODEV; found: -- 1.7.8 -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
