Hi, On Mon, Oct 28, 2013 at 06:13:00PM -0700, David Cohen wrote: > DWC3 requires buffer size to be aligned to maxpacketsize of an out > endpoint. ffs_epfile_io() needs to pad epout buffer to match above > condition if DWC3 controller is used. > > This patch solves an specific situation but a more generic solution > should be found. > > Signed-off-by: David Cohen <[email protected]> > --- > drivers/usb/gadget/f_fs.c | 19 +++++++++++++++++++ > 1 file changed, 19 insertions(+) > > diff --git a/drivers/usb/gadget/f_fs.c b/drivers/usb/gadget/f_fs.c > index 75e4b78..33880e6 100644 > --- a/drivers/usb/gadget/f_fs.c > +++ b/drivers/usb/gadget/f_fs.c > @@ -27,6 +27,7 @@ > #include <linux/usb/composite.h> > #include <linux/usb/functionfs.h> > > +#include "gadget_chips.h" > > #define FUNCTIONFS_MAGIC 0xa647361 /* Chosen by a honest dice roll ;) */ > > @@ -755,10 +756,12 @@ 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 +797,22 @@ first_try: > goto error; > } > > + /* > + * DWC3 requires buffer size to be aligned to maxpacketsize > + * of an out endpoint. > + * FIXME: a more generic solution might be necessary. > + */
see, gadget drivers shouldn't have to know about DWC3 at all. They need
to know that current UDC has a quirk where EP OUT transactions need to
be aligned to wMaxPacketSize, so what I was expecting to see here was:
if (test_bit(USB_GADGET_QUIRK_EP_OUT_ALIGNED_SIZE,
&gadget->qirks) &&
!IS_ALIGNED(len, ep->ep->desc->wMaxPacketSize))
len = align_length(orig_len, wMaxPacketSize);
--
balbi
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