linux/drivers/mtd/nand
Sascha Hauer 0fddf9ad06 mtd: rawnand: gpmi: Set WAIT_FOR_READY timeout based on program/erase times
06781a5026 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.

This is for now the easiest and most obvious way to fix the driver.
There's room for improvements though: The NAND_OP_WAITRDY_INSTR tells us
the desired timeout for the current operation, so we could program the
timeout dynamically for each operation instead of setting a fixed
timeout. Also we could wire up the interrupt handler to actually detect
and forward timeouts occurred when waiting for the chip being ready.

As a sidenote I verified that the change in 06781a5026 is really
correct. I wired up the interrupt handler in my tree and measured the
time between starting the operation and the timeout interrupt handler
coming in. The time increases 41us with each step in the timeout
register which corresponds to 4096 clock cycles with the 99MHz clock
that I have.

Fixes: 06781a5026 ("mtd: rawnand: gpmi: Fix setting busy timeout setting")
Fixes: b120612206 ("mtd: rawniand: gpmi: use core timings instead of an empirical derivation")
Cc: stable@vger.kernel.org
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Acked-by: Han Xu <han.xu@nxp.com>
Tested-by: Tomasz Moń <tomasz.mon@camlingroup.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2022-07-15 17:41:11 +02:00
..
onenand mtd: onenand: Check for error irq 2022-01-23 16:37:17 +01:00
raw mtd: rawnand: gpmi: Set WAIT_FOR_READY timeout based on program/erase times 2022-07-15 17:41:11 +02:00
spi mtd: spinand: Add support for XTX XT26G0xA 2022-04-21 09:34:12 +02:00
bbt.c mtd: nand: bbt: Fix corner case in bad block table handling 2021-05-10 18:20:54 +02:00
core.c Topic branch bringing-in changes related to the support of ECC engines 2022-02-18 15:11:12 +01:00
ecc-mtk.c MTD core changes: 2022-05-24 14:31:29 -07:00
ecc-mxic.c mtd: nand: mxic-ecc: make two read-only arrays static const 2022-03-14 17:01:58 +01:00
ecc-sw-bch.c mtd: nand: ecc-bch: Use the public nsteps field 2021-03-11 09:37:28 +01:00
ecc-sw-hamming.c mtd: rawnand: Let callers use the bare Hamming helpers 2021-10-15 12:20:59 +02:00
ecc.c mtd: nand: ecc: Provide a helper to retrieve a pilelined engine device 2022-02-09 09:49:36 +01:00
Kconfig mtd: nand: MTD_NAND_ECC_MEDIATEK should depend on ARCH_MEDIATEK 2022-05-12 16:43:04 +02:00
Makefile mtd: nand: make mtk_ecc.c a separated module 2022-04-27 18:12:35 +02:00