On Fri, 19 Aug 2011, Felipe Balbi wrote:
> > I think the best value would be FSG_BUFLEN / the bulk maxpacket size
> > (always 1024 for SuperSpeed) -- but no more than the maximum allowed
> > value (either 15 or 16, I forget which).
> >
> > We also need to figure out whether the UDC driver should pay attention
> > to the bMaxBurst value. If it doesn't support bursting, it would have
> > to set that field to 0.
>
> ok... how about the below:
>
> From c7176d97fe781f7fe0b21ca15ef7f449e5a7598e Mon Sep 17 00:00:00 2001
> From: Felipe Balbi <balbi@xxxxxx>
> Date: Wed, 3 Aug 2011 14:33:27 +0300
> Subject: [PATCH] usb: gadget: storage: add superspeed support
> Organization: Texas Instruments\n
When did TI add the \n to the end of their name? :-)
> this patch adds superspeed descriptors for the
> storage gadgets.
>
> Signed-off-by: Felipe Balbi <balbi@xxxxxx>
> ---
> drivers/usb/gadget/f_mass_storage.c | 24 ++++++++++
> drivers/usb/gadget/file_storage.c | 29 +++++++++++-
> drivers/usb/gadget/mass_storage.c | 2 +-
> drivers/usb/gadget/storage_common.c | 85 ++++++++++++++++++++++++++++++++++-
> 4 files changed, 134 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/usb/gadget/f_mass_storage.c b/drivers/usb/gadget/f_mass_storage.c
> index 5b93395..9c12234 100644
> --- a/drivers/usb/gadget/f_mass_storage.c
> +++ b/drivers/usb/gadget/f_mass_storage.c
> @@ -3019,6 +3019,30 @@ static int fsg_bind(struct usb_configuration *c, struct usb_function *f)
> }
> }
>
> + if (gadget_is_superspeed(gadget)) {
> + u8 max_burst;
Why not just int, or unsigned?
> + /* Calculate bMaxBurst, we know packet size is 1024 */
> + max_burst = (FSG_BUFLEN << (FSG_NUM_BUFFERS - 1) >>
> + (__ffs(1024)));
There's no reason to do a bit-shift by FSG_NUM_BUFFERS - 1. This
should simply be:
max_burst = FSG_BUFLEN / 1024;
You can trust the compiler to do the division at compile time, and
don't bother worrying about right shifts.
> + max_burst = min_t(u8, max_burst, 15);
In fact, you could even do:
max_burst = min_t(unsigned, FSG_BUFLEN / 1024, 15);
Since FSG_BUFLEN is 16384, this will always come out to 15 anyway.
Alan Stern
P.S.: Just in case you weren't aware, the patch you posted was
incomplete: It made some changes to g_file_storage and other changes to
g_mass_storage, but it didn't make all changes to both.
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