diff options
| author | Peter Chen <peter.chen@nxp.com> | 2019-12-12 16:35:03 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-01-15 10:39:22 +0100 |
| commit | d2450c6937018d40d4111fe830fa48d4ddceb8d0 (patch) | |
| tree | af6f8a5171e0ff16d362cf1b74ab4d74430658e5 /drivers/usb/gadget/function | |
| parent | a02497033e8e04c30501abb78c92d862982b9912 (diff) | |
| download | linux-d2450c6937018d40d4111fe830fa48d4ddceb8d0.tar.bz2 | |
usb: gadget: f_fs: set req->num_sgs as 0 for non-sg transfer
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>
Diffstat (limited to 'drivers/usb/gadget/function')
| -rw-r--r-- | drivers/usb/gadget/function/f_fs.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/usb/gadget/function/f_fs.c b/drivers/usb/gadget/function/f_fs.c index 0bbccac94d6c..6f8b67e61771 100644 --- 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 *file, struct ffs_io_data *io_data) 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 *file, struct ffs_io_data *io_data) req->num_sgs = io_data->sgt.nents; } else { req->buf = data; + req->num_sgs = 0; } req->length = data_len; |