Hi,
On Sun, Apr 03, 2011 at 09:48:51PM +0300, Felipe Balbi wrote:
> > There's no way to avoid short packets. If the hardware can't handle
> > short packets, it is completely broken and there's no sense even trying
> > to use it. As an example, consider that the CBW packet is 31 bytes and
> > therefore will be short at any speed.
>
> This is good point.
Now that I look closer at the code, in case of CBW, we set outreq->length
to ep->maxpacket:
/* Queue a request to read a Bulk-only CBW */
set_bulk_out_req_length(fsg, bh, USB_BULK_CB_WRAP_LEN);
set_bulk_out_req_length(), alignes the size of the request to
ep->maxpacket:
static void set_bulk_out_req_length(struct fsg_dev *fsg,
struct fsg_buffhd *bh, unsigned int length)
{
unsigned int rem;
bh->bulk_out_intended_length = length;
rem = length % fsg->bulk_out_maxpacket;
if (rem > 0)
length += fsg->bulk_out_maxpacket - rem;
bh->outreq->length = length;
}
So, why didn't we use the same on the other parts of the code ? I mean:
diff --git a/drivers/usb/gadget/file_storage.c b/drivers/usb/gadget/file_storage.c
index a6eacb5..24e5b49 100644
--- a/drivers/usb/gadget/file_storage.c
+++ b/drivers/usb/gadget/file_storage.c
@@ -1349,8 +1349,7 @@ static int do_write(struct fsg_dev *fsg)
/* amount is always divisible by 512, hence by
* the bulk-out maxpacket size */
- bh->outreq->length = bh->bulk_out_intended_length =
- amount;
+ set_bulk_out_req_length(fsg, bh, amount);
bh->outreq->short_not_ok = 1;
start_transfer(fsg, fsg->bulk_out, bh->outreq,
&bh->outreq_busy, &bh->state);
@@ -2010,8 +2009,7 @@ static int throw_away_data(struct fsg_dev *fsg)
/* amount is always divisible by 512, hence by
* the bulk-out maxpacket size */
- bh->outreq->length = bh->bulk_out_intended_length =
- amount;
+ set_bulk_out_req_length(fsg, bh, amount);
bh->outreq->short_not_ok = 1;
start_transfer(fsg, fsg->bulk_out, bh->outreq,
&bh->outreq_busy, &bh->state);
With that, my USB3 controller would be happy.
--
balbi
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