| From d2450c6937018d40d4111fe830fa48d4ddceb8d0 Mon Sep 17 00:00:00 2001 |
| From: Peter Chen <peter.chen@nxp.com> |
| Date: Thu, 12 Dec 2019 16:35:03 +0800 |
| Subject: usb: gadget: f_fs: set req->num_sgs as 0 for non-sg transfer |
| |
| From: Peter Chen <peter.chen@nxp.com> |
| |
| commit d2450c6937018d40d4111fe830fa48d4ddceb8d0 upstream. |
| |
| The UDC core uses req->num_sgs to judge if scatter buffer list is used. |
| Eg: usb_gadget_map_request_by_dev. For f_fs sync io mode, the request |
| is re-used for each request, so if the 1st request->length > PAGE_SIZE, |
| and the 2nd request->length is <= PAGE_SIZE, the f_fs uses the 1st |
| req->num_sgs for the 2nd request, it causes the UDC core get the wrong |
| req->num_sgs value (The 2nd request doesn't use sg). For f_fs async |
| io mode, it is not harm to initialize req->num_sgs as 0 either, in case, |
| the UDC driver doesn't zeroed request structure. |
| |
| Cc: Jun Li <jun.li@nxp.com> |
| Cc: stable <stable@vger.kernel.org> |
| Fixes: 772a7a724f69 ("usb: gadget: f_fs: Allow scatter-gather buffers") |
| Signed-off-by: Peter Chen <peter.chen@nxp.com> |
| Signed-off-by: Felipe Balbi <balbi@kernel.org> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| drivers/usb/gadget/function/f_fs.c | 2 ++ |
| 1 file changed, 2 insertions(+) |
| |
| --- a/drivers/usb/gadget/function/f_fs.c |
| +++ b/drivers/usb/gadget/function/f_fs.c |
| @@ -1062,6 +1062,7 @@ static ssize_t ffs_epfile_io(struct file |
| req->num_sgs = io_data->sgt.nents; |
| } else { |
| req->buf = data; |
| + req->num_sgs = 0; |
| } |
| req->length = data_len; |
| |
| @@ -1105,6 +1106,7 @@ static ssize_t ffs_epfile_io(struct file |
| req->num_sgs = io_data->sgt.nents; |
| } else { |
| req->buf = data; |
| + req->num_sgs = 0; |
| } |
| req->length = data_len; |
| |