[PATCH] mtd: rawnand: gpmi: Set WAIT_FOR_READY timeout based on program/erase times

[Tomasz Moń]

On Fri, 2022-07-01 at 13:03 +0200, Sascha Hauer wrote:
> 06781a5026350 Fixes the calculation of the DEVICE_BUSY_TIMEOUT register
> value from busy_timeout_cycles. busy_timeout_cycles is calculated wrong
> though: It is calculated based on the maximum page read time, but the
> timeout is also used for page write and block erase operations which
> require orders of magnitude bigger timeouts.
> 
> Fix this by calculating busy_timeout_cycles from the maximum of
> tBERS_max and tPROG_max.

06781a5026350 was merged in v5.19-rc4 and then was picked up by several
stable kernels, including v5.15.51. After we have upgraded to v5.15.51
we have observed the issue that Sascha mentioned in his email [1].

As the v5.19-rc6 was released yesterday and this fix is still not
applied, the v5.19-rc6 (and all stable kernels that picked up the
backport) causes NAND flash data loss on imx targets.

I have backported this patch to our internal v5.15.51 based kernel on
4th July 2022 and I can confirm that it does indeed solve the NAND data
loss on imx targets.

Is it possible for this patch to make it to the v5.19-rc7?

> Fixes: 06781a5026350 ("mtd: rawnand: gpmi: Fix setting busy timeout setting")
> Fixes: b1206122069aa ("mtd: rawniand: gpmi: use core timings instead of an empirical derivation")
> Cc: stable at vger.kernel.org
> Signed-off-by: Sascha Hauer <s.hauer at pengutronix.de>

Tested-by: Tomasz Moń <tomasz.mon at camlingroup.com>

[1] https://lore.kernel.org/linux-mtd/20220701091909.GE2387@pengutronix.de/