From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marek Vasut Date: Sat, 11 Apr 2015 19:01:04 +0200 Subject: [U-Boot] [PATCH] usb: fix first descriptor fetch error handling In-Reply-To: <1428550069-9761-1-git-send-email-swarren@wwwdotorg.org> References: <1428550069-9761-1-git-send-email-swarren@wwwdotorg.org> Message-ID: <201504111901.05012.marex@denx.de> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de 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 > Signed-off-by: Stephen Warren Applied to u-boot-usb/next, thanks! Best regards, Marek Vasut