[U-Boot] [PATCH] usb: fix first descriptor fetch error handling

Marek Vasut marex at denx.de
Sat Apr 11 19:01:04 CEST 2015


On Thursday, April 09, 2015 at 05:27:49 AM, Stephen Warren wrote:
> When fetching the first descriptor from a new device, only validate that
> we received at least 8 bytes, not that we received the entire descriptor.
> The reasoning is:
> - The code only uses fields in the first 8 bytes, so that's all we need
>   to have fetched at this stage.
> - The smallest maxpacket size is 8 bytes. Before we know the actual
>   maxpacket the device uses, the USB controller may only accept a single
>   packet (see the DWC2 note in the comment added in the commit).
>   Consequently we are only guaranteed to receive 1 packet (at least 8
>   bytes) even in a non-error case.
> 
> Fixes: 1a7758044b04 ("usb: Early failure when the first descriptor read
> fails or is invalid")
> Cc: Paul Kocialkowski <contact at paulk.fr>
> Signed-off-by: Stephen Warren <swarren at wwwdotorg.org>

Applied to u-boot-usb/next, thanks!

Best regards,
Marek Vasut


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