[PATCH v3 2/3] usb: ffs: check quirk to pad epout buf size when not aligned to maxpacketsize

From: David Cohen
Date: Wed Oct 30 2013 - 13:04:05 EST


Check gadget.quirk_ep_out_aligned_size to decide if buffer size requires
to be aligned to maxpacketsize of an out endpoint. ffs_epfile_io() needs
to pad epout buffer to match above condition if quirk is found.

Signed-off-by: David Cohen <david.a.cohen@xxxxxxxxxxxxxxx>
---
drivers/usb/gadget/f_fs.c | 17 +++++++++++++++++
1 file changed, 17 insertions(+)

diff --git a/drivers/usb/gadget/f_fs.c b/drivers/usb/gadget/f_fs.c
index 75e4b78..b49dd55 100644
--- a/drivers/usb/gadget/f_fs.c
+++ b/drivers/usb/gadget/f_fs.c
@@ -755,10 +755,12 @@ static ssize_t ffs_epfile_io(struct file *file,
char __user *buf, size_t len, int read)
{
struct ffs_epfile *epfile = file->private_data;
+ struct usb_gadget *gadget = epfile->ffs->gadget;
struct ffs_ep *ep;
char *data = NULL;
ssize_t ret;
int halt;
+ size_t orig_len = len;

goto first_try;
do {
@@ -794,6 +796,21 @@ first_try:
goto error;
}

+ /*
+ * Controller requires buffer size to be aligned to
+ * maxpacketsize of an out endpoint.
+ */
+ if (gadget->quirk_ep_out_aligned_size && read &&
+ !IS_ALIGNED(len, ep->ep->desc->wMaxPacketSize)) {
+ size_t old_len = len;
+ len = roundup(orig_len,
+ (size_t)ep->ep->desc->wMaxPacketSize);
+ if (unlikely(data) && len > old_len) {
+ kfree(data);
+ data = NULL;
+ }
+ }
+
/* Allocate & copy */
if (!halt && !data) {
data = kzalloc(len, GFP_KERNEL);
--
1.8.4.rc3

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