From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tom Rini Date: Fri, 15 Jun 2012 07:30:33 -0700 Subject: [U-Boot] [PATCH 2/4] cache_v7: Check for dcache enablement in dcache flush functions In-Reply-To: <201206151625.50857.marex@denx.de> References: <1339700507-26700-1-git-send-email-trini@ti.com> <4FDB41BE.40204@ti.com> <201206151625.50857.marex@denx.de> Message-ID: <4FDB4709.1050607@ti.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 06/15/2012 07:25 AM, Marek Vasut wrote: > Dear Tom Rini, > >> On 06/14/2012 10:48 PM, R, Sricharan wrote: >>> Hi Tom, >>> >>> On Fri, Jun 15, 2012 at 12:31 AM, Tom Rini wrote: >>>> If we are built with D-CACHE enabled but have run 'dcache off' and then >>>> attempt to flush unaligned regions we spam the console with problems >>>> that aren't true (as the cache was off). >>>> >>> Today we do cache maintenance operations after the dcache is turned >>> off. One example is before jumping to kernel, we try to invalidate the >>> caches, in cache turned off state. So with this patch those >>> maintenance calls will do nothing, which is not correct. >> >> Ah yes, But, shouldn't we be doing these same operations as part of >> turning the cache off? >> >>> If it is a problem with unaligned regions, then that is the only >>> >>> thing to be fixed >>> >>> right ?. Just trying to understand why this change is required ? >> >> The problem is that within the USB/network/filesystem stacks we have a >> lot of not cache safe alignments apparently. Without this every '#' of >> a tftp gives a screen full of error printfs. So tftp'ing a kernel takes >> minutes, not seconds, to complete. > > I think we should augment uboot to disallow tftp, fatload etc. to cache- > unaligned address when caches are on ... this'd squash away the need for any > shitty bounce buffers right away. Tom, will you be able to implement it, pretty > please? But that's not the problem. The problem is all of the stuff going on within the USB/networking stack. -- Tom