From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stefan Roese Date: Thu, 13 Aug 2015 13:21:05 +0200 Subject: [U-Boot] [PATCH V6] sf: Turn SPI flash chip into 3-Byte address mode In-Reply-To: References: <1439360292-32085-1-git-send-email-B48286@freescale.com> Message-ID: <55CC7DA1.1030605@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 13.08.2015 12:50, Hou Zhiqiang wrote: >> -----Original Message----- >> From: Siva Durga Prasad Paladugu [mailto:siva.durga.paladugu at xilinx.com] >> Sent: 2015?8?13? 17:18 >> To: Hou Zhiqiang-B48286; u-boot at lists.denx.de; jteki at openedev.com >> Cc: Sun York-R58495; Hu Mingkai-B21284; nofooter >> Subject: RE: [PATCH V6] sf: Turn SPI flash chip into 3-Byte address mode >> >> Hi Zhejiang/Jagan, >> >> I think it would be good to extend this further to support 4-byte >> addressing in u-boot also. >> This would be based on the driver, We can get the data that whether the >> controller supports 4-byte or not from the driver level(through slave >> struct) and enable 4 byte addressing here based on that. >> > > That is a long way, and I don't think it is necessary for U-Boot. The U-Boot > work well using BAR to address more than 16MiB flash. > This patch focus on the address mode issue when warm boot up base on the BAR > address mode. Please correct me if I'm wrong, but AFAIU this BAR thing (CONFIG_SPI_FLASH_BAR) doesn't support to address e.g. a 64MiB SPI flash contiguously. Only 16MiB areas. So for example its not possible to put UBI/UBIFS in such a big partition. I have to support Siva here. We really should try to support this 4-byte mode correctly. This can't be too hard. Thanks, Stefan