USB: gadget: Fix "scheduling while atomic" bugs in ci13xxx_udc

dma_pool_alloc() require sleeping context when called with GFP_KERNEL
argument.  Hence release the spin lock before calling dma_pool_alloc().

usb_ep_alloc_request can also be called with non-atomic GFP flags.  Hence
get rid off spin lock while allocation request memory.

Use GFP_ATOMIC flag for allocating request for ep0 in interrupt handler.

Signed-off-by: Pavankumar Kondeti <pkondeti@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 3 insertions, 6 deletions

diff --git a/drivers/usb/gadget/ci13xxx_udc.c b/drivers/usb/gadget/ci13xxx_udc.c
index 4e9ec7d256fd..d19537a0613d 100644
--- a/drivers/usb/gadget/ci13xxx_udc.c
+++ b/drivers/usb/gadget/ci13xxx_udc.c
@@ -1626,7 +1626,7 @@ __acquires(udc->lock)
         spin_unlock(udc->lock);
         retval = usb_ep_enable(&mEp->ep, &ctrl_endpt_desc);
         if (!retval) {
-                mEp->status = usb_ep_alloc_request(&mEp->ep, GFP_KERNEL);
+                mEp->status = usb_ep_alloc_request(&mEp->ep, GFP_ATOMIC);
                 if (mEp->status == NULL) {
                         usb_ep_disable(&mEp->ep);
                         retval = -ENOMEM;
@@ -2055,7 +2055,6 @@ static struct usb_request *ep_alloc_request(struct usb_ep *ep, gfp_t gfp_flags)
 {
         struct ci13xxx_ep  *mEp  = container_of(ep, struct ci13xxx_ep, ep);
         struct ci13xxx_req *mReq = NULL;
-        unsigned long flags;
 
         trace("%p, %i", ep, gfp_flags);
 
@@ -2064,8 +2063,6 @@ static struct usb_request *ep_alloc_request(struct usb_ep *ep, gfp_t gfp_flags)
                 return NULL;
         }
 
-        spin_lock_irqsave(mEp->lock, flags);
-
         mReq = kzalloc(sizeof(struct ci13xxx_req), gfp_flags);
         if (mReq != NULL) {
                 INIT_LIST_HEAD(&mReq->queue);
@@ -2080,8 +2077,6 @@ static struct usb_request *ep_alloc_request(struct usb_ep *ep, gfp_t gfp_flags)
 
         dbg_event(_usb_addr(mEp), "ALLOC", mReq == NULL);
 
-        spin_unlock_irqrestore(mEp->lock, flags);
-
         return (mReq == NULL) ? NULL : &mReq->req;
 }
 
@@ -2404,9 +2399,11 @@ int usb_gadget_probe_driver(struct usb_gadget_driver *driver,
                 /* this allocation cannot be random */
                 for (k = RX; k <= TX; k++) {
                         INIT_LIST_HEAD(&mEp->qh[k].queue);
+                        spin_unlock_irqrestore(udc->lock, flags);
                         mEp->qh[k].ptr = dma_pool_alloc(udc->qh_pool,
                                                         GFP_KERNEL,
                                                         &mEp->qh[k].dma);
+                        spin_lock_irqsave(udc->lock, flags);
                         if (mEp->qh[k].ptr == NULL)
                                 retval = -ENOMEM;
                         else