+ 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