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

drivers/usb/gadget/file_storage.c

+9 −0
Original line number Diff line number Diff line
@@ -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)