diff options
| author | Alan Stern <stern@rowland.harvard.edu> | 2006-03-23 15:07:25 -0500 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2006-04-14 11:12:20 -0700 |
| commit | 14cd5f8e85e90c9dead2393377b9a2c23131e0ce (patch) | |
| tree | f83f012b51ecdcf2415c3886a05aad580391ef92 /drivers | |
| parent | 70ffe6e14d7c5db84b92841471ce6fd0200010cd (diff) | |
| download | linux-14cd5f8e85e90c9dead2393377b9a2c23131e0ce.tar.gz | |
[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: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/usb/gadget/file_storage.c | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/drivers/usb/gadget/file_storage.c b/drivers/usb/gadget/file_storage.c index eb2821542b7c4a..b6d920f349ea70 100644 --- a/drivers/usb/gadget/file_storage.c +++ b/drivers/usb/gadget/file_storage.c @@ -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) |