From mboxrd@z Thu Jan 1 00:00:00 1970 From: Goldschmidt Simon Date: Tue, 5 Dec 2017 06:20:59 +0000 Subject: [U-Boot] [PATCH] sf: ensure flash device is in 3-byte address mode Message-ID: List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de + Lukasz (as a reviewer of my patch[1]) On Mon, Dec 4, 2017 at 8:20, Jagan Teki wrote: > This is the patch[1] for 4-byte addressing, but I would wonder how can proceed > operations with 4-byte if we disable during probe. > > [1] http://git.denx.de/?p=u-boot- > spi.git;a=commitdiff;h=fd0c22a90772379c4c11ba09347d36cc8ee17dca OK, so your patch does something different than what I did. I was trying to keep the change to U-Boot as small as possible, only fixing this issue I was seeing: After a soft-reboot where the SPI chip was not reset, it is left in 4-byte addressing mode (linux uses this mode, obviously). Remember that 4-byte mode is not a permanent setting, so we can enter and leave it any time we like by issuing a command. U-Boot uses the Bank Address Register (BAR) for spi flash chips with more than 16 MByte, so it impclitly assumes that the chip is in 3-byte address mode. As I see it, your patch is worth a discussion named "should we use 4-byte addressing mode on spi flash chips?". I do think this is a better alternative than writing BAR! But this change probably needs discussion and testing. Until we discussed and tested that, could we push my patch[1] into v2018.01? This is really a rather tiny bugfix I need for soft reboot, compared to using 4-byte address mode. [1] https://patchwork.ozlabs.org/patch/826919/ Thanks, Simon