usb gadget stack: remove usb_ep_*_buffer(), part 2

This patch removes controller driver infrastructure which supported
the now-removed usb_ep_{alloc,free}_buffer() calls.

As can be seen, many of the implementations of this were broken to
various degrees.  Many didn't properly return dma-coherent mappings;
those which did so were necessarily ugly because of bogosity in the
underlying dma_free_coherent() calls ... which on many platforms
can't be called from the same contexts (notably in_irq) from which
their dma_alloc_coherent() sibling can be called.

The main potential downside of removing this is that gadget drivers
wouldn't have specific knowledge that the controller drivers have:
endpoints that aren't dma-capable don't need any dma mappings at all.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 0 insertions, 21 deletions

diff --git a/drivers/usb/gadget/at91_udc.c b/drivers/usb/gadget/at91_udc.c
index ba163f35bf21..63d7d6568699 100644
--- a/drivers/usb/gadget/at91_udc.c
+++ b/drivers/usb/gadget/at91_udc.c
@@ -601,25 +601,6 @@ static void at91_ep_free_request(struct usb_ep *_ep, struct usb_request *_req)
         kfree(req);
 }
 
-static void *at91_ep_alloc_buffer(
-        struct usb_ep *_ep,
-        unsigned bytes,
-        dma_addr_t *dma,
-        gfp_t gfp_flags)
-{
-        *dma = ~0;
-        return kmalloc(bytes, gfp_flags);
-}
-
-static void at91_ep_free_buffer(
-        struct usb_ep *ep,
-        void *buf,
-        dma_addr_t dma,
-        unsigned bytes)
-{
-        kfree(buf);
-}
-
 static int at91_ep_queue(struct usb_ep *_ep,
                         struct usb_request *_req, gfp_t gfp_flags)
 {
@@ -788,8 +769,6 @@ static const struct usb_ep_ops at91_ep_ops = {
         .disable        = at91_ep_disable,
         .alloc_request  = at91_ep_alloc_request,
         .free_request   = at91_ep_free_request,
-        .alloc_buffer   = at91_ep_alloc_buffer,
-        .free_buffer    = at91_ep_free_buffer,
         .queue          = at91_ep_queue,
         .dequeue        = at91_ep_dequeue,
         .set_halt       = at91_ep_set_halt,