Commit 14cd5f8e authored by Alan Stern's avatar Alan Stern Committed by Greg Kroah-Hartman

[PATCH] USB: g_file_storage: add comment about buffer allocation

This patch (as664) adds a comment to file_storage.c, noting that the
driver is slightly non-portable because it assumes that a buffer
allocated for a bulk-in endpoint will also be useable for a bulk-out
endpoint.
Signed-off-by: default avatarAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 70ffe6e1
......@@ -71,6 +71,12 @@
* requirement amounts to two 16K buffers, size configurable by a parameter.
* Support is included for both full-speed and high-speed operation.
*
* Note that the driver is slightly non-portable in that it assumes a
* single memory/DMA buffer will be useable for bulk-in, bulk-out, and
* interrupt-in endpoints. With most device controllers this isn't an
* issue, but there may be some with hardware restrictions that prevent
* a buffer from being used by more than one endpoint.
*
* Module options:
*
* file=filename[,filename...]
......@@ -3956,6 +3962,9 @@ static int __init fsg_bind(struct usb_gadget *gadget)
for (i = 0; i < NUM_BUFFERS; ++i) {
struct fsg_buffhd *bh = &fsg->buffhds[i];
/* Allocate for the bulk-in endpoint. We assume that
* the buffer will also work with the bulk-out (and
* interrupt-in) endpoint. */
bh->buf = usb_ep_alloc_buffer(fsg->bulk_in, mod_data.buflen,
&bh->dma, GFP_KERNEL);
if (!bh->buf)
......
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