From mboxrd@z Thu Jan 1 00:00:00 1970 From: Laurence Withers Date: Thu, 18 Aug 2011 15:20:09 +0000 Subject: [U-Boot] [PATCH v3 1/8] da850: indicate cache usage disable in config file In-Reply-To: References: <1313590455-32737-1-git-send-email-nagabhushana.netagunte@ti.com> <1313590455-32737-2-git-send-email-nagabhushana.netagunte@ti.com> Message-ID: <20110818152008.GI7769@guralp.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de On Thu, Aug 18, 2011 at 11:13:19AM -0400, Ben Gardiner wrote: > I understand that both Laurence and Stefan (cc'd) have confirmed that > there dcache issues with the EMA; I am assuming that the 'issue' > results in a delay in tftp'ing... No; the issue was that packets were being sent on to the wire with incorrect IP checksums. It twigged that the problem was cache coherency when I put a full hexdump of each outgoing packet in and suddenly the outbound packets started being valid. > Disabling the caches will slow down decompression which will slow down > boot overall when booting from flash. > > Rather than masking the issue by disabling caches and slowing down > u-boot for it's users perhaps TI should be fixing the EMAC drivers' > cache bugs instead? Indeed, the correct solution is to properly manage the net buffers with respect to the cache, although I have not attempted that change myself. I have seen some patches start to flow that make changes in drivers to work correctly with caches enabled, such as http://lists.denx.de/pipermail/u-boot/2011-August/098484.html . Bye for now, -- Laurence Withers, http://www.guralp.com/ Direct tel:+447753988197 or tel:+443333408643 Software Engineer General support queries: CMG-DCM CMG-EAM CMG-NAM