Peter Chen peter.chen@nxp.com writes:
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).
We set req->num_sgs as 0 for each request at non-sg transfer case to fix it.
The patch, however, is *removing* initialization to 0...
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
drivers/usb/gadget/function/f_fs.c | 1 - 1 file changed, 1 deletion(-)
diff --git a/drivers/usb/gadget/function/f_fs.c b/drivers/usb/gadget/function/f_fs.c index eedd926cc578..b5a1bfc2fc7e 100644 --- a/drivers/usb/gadget/function/f_fs.c +++ b/drivers/usb/gadget/function/f_fs.c @@ -1106,7 +1106,6 @@ 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;... this doesn't seem to match your commit log. Care to explain?
Sorry, I did not check the patch when I formatted it. I need to pay more attention to it next time. I will send it again.
Peter