Re: [PATCH] usb: gadget: f_midi: Fixed a bug when buflen was smaller than wMaxPacketSize

From	Clemens Ladisch <clemens@ladisch.de>
Newsgroups	linux.kernel
Subject	Re: [PATCH] usb: gadget: f_midi: Fixed a bug when buflen was smaller than wMaxPacketSize
Date	2016-03-15 10:50 +0100
Message-ID	<rcTLY-fp-5@gated-at.bofh.it> (permalink)
References	<raS7E-44y-5@gated-at.bofh.it> <rbElZ-54U-51@gated-at.bofh.it> <rcD4v-5Mh-23@gated-at.bofh.it>
Organization	linux.* mail to news gateway

Show all headers | View raw

Felipe Ferreri Tonello wrote:
> On 11/03/16 23:07, Michal Nazarewicz wrote:
>> I’m also wondering whether it would be beneficial to get rid of buflen
>> all together and use wMaxPacketSie for in endpoints as well?  Is that
>> feasible?
>
> Yes, we could just remove the buflen parameter.
>
> The only scenario where I can see buflen been "useful" is if the user
> wants to have a smaller buffer size for the OUT endpoint. Should we
> support this case or not?

Splitting data into multiple packets would not make sense from
a performance perspective.  The only possible reason would be to work
around a (theoretical) bug in some host software that does not handle
larger buffers, but there aren't that many host implementations, and I
am not aware of any with such a bug.

Regards,
Clemens

Back to linux.kernel | Previous | Next — Previous in thread | Find similar | Unroll thread

Thread

[PATCH] usb: gadget: f_midi: Fixed a bug when buflen was smaller than wMaxPacketSize "Felipe F. Tonello" <eu@felipetonello.com> - 2016-03-09 20:40 +0100
  Re: [PATCH] usb: gadget: f_midi: Fixed a bug when buflen was smaller  than wMaxPacketSize Steve Calfee <stevecalfee@gmail.com> - 2016-03-09 23:50 +0100
    Re: [PATCH] usb: gadget: f_midi: Fixed a bug when buflen was smaller  than wMaxPacketSize Felipe Ferreri Tonello <eu@felipetonello.com> - 2016-03-10 10:30 +0100
    Re: [PATCH] usb: gadget: f_midi: Fixed a bug when buflen was smaller  than wMaxPacketSize Clemens Ladisch <clemens@ladisch.de> - 2016-03-11 09:50 +0100
  Re: [PATCH] usb: gadget: f_midi: Fixed a bug when buflen was smaller than wMaxPacketSize Michal Nazarewicz <mina86@mina86.com> - 2016-03-12 00:10 +0100
    Re: [PATCH] usb: gadget: f_midi: Fixed a bug when buflen was smaller  than wMaxPacketSize Felipe Ferreri Tonello <eu@felipetonello.com> - 2016-03-14 17:00 +0100
      Re: [PATCH] usb: gadget: f_midi: Fixed a bug when buflen was smaller  than wMaxPacketSize Clemens Ladisch <clemens@ladisch.de> - 2016-03-15 10:50 +0100

csiph-web