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From: Marek Vasut <marex@denx.de>
To: u-boot@lists.denx.de
Subject: [U-Boot] [PATCH 1/7] usb: increase USB descriptor buffer size
Date: Sun, 13 Dec 2015 19:49:30 +0100	[thread overview]
Message-ID: <201512131949.30977.marex@denx.de> (raw)
In-Reply-To: <2415535.ONnvDgm0Am@pebbles.site>

On Sunday, December 13, 2015 at 07:35:19 PM, Stefan Bruens wrote:
> On Sunday 13 December 2015 05:49:24 Marek Vasut wrote:
> > On Sunday, December 13, 2015 at 05:47:18 AM, Stefan Br?ns wrote:
> > > The configuration descriptor includes all interface, endpoint and
> > > auxiliary descriptors (e.g. report, union) so 512 may not be enough.
> > > 
> > > Signed-off-by: Stefan Br?ns <stefan.bruens@rwth-aachen.de>
> > 
> > Can the size be determined in a dynamic manner instead of this ad-hoc
> > random number ?
> 
> Currently the buffer is allocated on the stack with
> ALLOC_CACHE_ALIGN_BUFFER in usb_select_config(... The buffer is passed to
> usb_get_configuration_no(...), but the buffer size is implicit.
> 
> usb_get_configuration_no(...) already determines and checks the descriptor
> size, but as it can not readjust the buffer it just bails out if it is
> to small.
> 
> The absolute maximum size for the descriptor is 64kB.
> 
> So yes, this is possible, but needs a little bit more work.

Do you feel like working on it ?

Best regards,
Marek Vasut

  reply	other threads:[~2015-12-13 18:49 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-12-13  4:47 [U-Boot] [PATCH 1/7] usb: increase USB descriptor buffer size Stefan Brüns
2015-12-13  4:49 ` Marek Vasut
2015-12-13 18:35   ` Stefan Bruens
2015-12-13 18:49     ` Marek Vasut [this message]
2015-12-18  1:07       ` [U-Boot] [PATCH] usb: Alloc buffer for USB descriptor dynamically Stefan Brüns
2015-12-18 20:19         ` Marek Vasut
2015-12-18 22:41         ` Simon Glass
2015-12-19 15:23           ` Stefan Bruens
2015-12-19 20:29             ` Simon Glass
2015-12-19 21:23               ` Stefan Bruens

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