From mboxrd@z Thu Jan 1 00:00:00 1970 From: stefano babic Date: Tue, 12 Oct 2010 16:57:49 +0200 Subject: [U-Boot] [PATCH 3/4] MX51: Add video support In-Reply-To: <20101012113409.5B97214F310@gemini.denx.de> References: <1286875504-9058-1-git-send-email-sbabic@denx.de> <1286875504-9058-2-git-send-email-sbabic@denx.de> <1286875504-9058-3-git-send-email-sbabic@denx.de> <1286875504-9058-4-git-send-email-sbabic@denx.de> <20101012113409.5B97214F310@gemini.denx.de> Message-ID: <4CB4776D.8050905@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 Wolfgang Denk wrote: > Dear Stefano Babic, > > In message <1286875504-9058-4-git-send-email-sbabic@denx.de> you wrote: >> Add framebuffer driver for the MX51 processor >> working on the IPUv3 internal graphic processor. > > Please add reference to original sources. Ok > > >> +/* >> + * Allocates the DRAM memory for the frame buffer. This buffer is remapped >> + * into a non-cached, non-buffered, memory region to allow palette and pixel >> + * writes to occur without flushing the cache. Once this area is remapped, >> + * all virtual memory access to the video memory should occur at the new region. > > Is this comment still valid for the U-Boot port? No, it is not. The comment makes no sense for u-boot. There is no allocation and malloc is not called, as the memory for the framebuffer is taken from the lcd_base variable. > > Does it work with both "dcache on" and "dcache off" settings? Well, as there is not yet support for L2-Cache on the MX51, we can say yes ;-). However, this range of memory is used directly from the IPU processor and not by the CPU, as well as in Linux without calling any function to invalidate the cache. But I agree, it should be tested again when support for L2-cache will be integrated. Stefano -- ===================================================================== DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany Phone: +49-8142-66989-0 Fax: +49-8142-66989-80 Email: office at denx.de =====================================================================