Some UDC drivers fails to queue a request if req->buf == NULL even for
ZLP requests. This patch add support for dummy request buffer in case of
ZLP request.
Signed-off-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
Signed-off-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx>
---
drivers/usb/gadget/f_fs.c | 5 +++++
1 files changed, 5 insertions(+), 0 deletions(-)
diff --git a/drivers/usb/gadget/f_fs.c b/drivers/usb/gadget/f_fs.c
index 1499f9e..f0a0907 100644
--- a/drivers/usb/gadget/f_fs.c
+++ b/drivers/usb/gadget/f_fs.c
@@ -356,6 +356,7 @@ static void ffs_ep0_complete(struct usb_ep *ep, struct usb_request *req)
complete_all(&ffs->ep0req_completion);
}
+static char ffs_tmp_buf[1];
static int __ffs_ep0_queue_wait(struct ffs_data *ffs, char *data, size_t len)
{
struct usb_request *req = ffs->ep0req;
@@ -368,6 +369,10 @@ static int __ffs_ep0_queue_wait(struct ffs_data *ffs, char *data, size_t len)
req->buf = data;
req->length = len;
+ /* UDC layer require to provide a buffer even for ZLP */
+ if (req->buf == NULL)
+ req->buf = ffs_tmp_buf;
+
INIT_COMPLETION(ffs->ep0req_completion);
ret = usb_ep_queue(ffs->gadget->ep0, req, GFP_ATOMIC);
--
1.7.1.569.g6f426
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