On Fri, Jul 15, 2022 at 07:22:09AM -0700, Guenter Roeck wrote: > On Tue, Jun 14, 2022 at 10:31:38AM +0200, Sascha Hauer wrote: > > The DEVICE_BUSY_TIMEOUT value is described in the Reference Manual as: > > > > | Timeout waiting for NAND Ready/Busy or ATA IRQ. Used in WAIT_FOR_READY > > | mode. This value is the number of GPMI_CLK cycles multiplied by 4096. > > > > So instead of multiplying the value in cycles with 4096, we have to > > divide it by that value. Use DIV_ROUND_UP to make sure we are on the > > safe side, especially when the calculated value in cycles is smaller > > than 4096 as typically the case. > > > > This bug likely never triggered because any timeout != 0 usually will > > do. In my case the busy timeout in cycles was originally calculated as > > 2408, which multiplied with 4096 is 0x968000. The lower 16 bits were > > taken for the 16 bit wide register field, so the register value was > > 0x8000. With 2970bf5a32f0 ("mtd: rawnand: gpmi: fix controller timings > > setting") however the value in cycles became 2384, which multiplied > > with 4096 is 0x950000. The lower 16 bit are 0x0 now resulting in an > > intermediate timeout when reading from NAND. > > > > Fixes: b1206122069aa ("mtd: rawnand: gpmi: use core timings instead of an empirical derivation") > > Cc: stable@xxxxxxxxxxxxxxx > > Signed-off-by: Sascha Hauer <s.hauer@xxxxxxxxxxxxxx> > > I see this patch was reverted in a set of rush stable releases, > but I still see it in the mainline kernel. Is it going to be reverted > there as well ? A fix has been sent, it was said to be picked up hopefully next week: https://lore.kernel.org/all/20220701110341.3094023-1-s.hauer@xxxxxxxxxxxxxx/ thanks, greg k-h