Hi Tokunori, ikegami.t@xxxxxxxxx wrote on Thu, 17 Mar 2022 00:54:54 +0900: > As pointed out by this bug report [1], buffered writes are now broken on > S29GL064N. This issue comes from a rework which switched from using chip_good() > to chip_ready(), because DQ true data 0xFF is read on S29GL064N and an error > returned by chip_good(). Vignesh, I believe you understand this issue better than I do, can you propose an improved commit log? > One way to solve the issue is to revert the change > partially to use chip_ready for S29GL064N. > > [1] https://lore.kernel.org/r/b687c259-6413-26c9-d4c9-b3afa69ea124@xxxxxxxxxxxxxx/ > > Fixes: dfeae1073583("mtd: cfi_cmdset_0002: Change write buffer to check correct value") > Signed-off-by: Tokunori Ikegami <ikegami.t@xxxxxxxxx> > Tested-by: Ahmad Fatoum <a.fatoum@xxxxxxxxxxxxxx> > Cc: stable@xxxxxxxxxxxxxxx > --- > drivers/mtd/chips/cfi_cmdset_0002.c | 25 +++++++++++++++++++++---- > 1 file changed, 21 insertions(+), 4 deletions(-) > > diff --git a/drivers/mtd/chips/cfi_cmdset_0002.c b/drivers/mtd/chips/cfi_cmdset_0002.c > index e68ddf0f7fc0..6c57f85e1b8e 100644 > --- a/drivers/mtd/chips/cfi_cmdset_0002.c > +++ b/drivers/mtd/chips/cfi_cmdset_0002.c > @@ -866,6 +866,23 @@ static int __xipram chip_check(struct map_info *map, struct flchip *chip, > chip_check(map, chip, addr, &datum); \ > }) > > +static bool __xipram cfi_use_chip_ready_for_write(struct map_info *map) At the very least I would call this function: cfi_use_chip_ready_for_writes() Yet, I still don't fully get what chip_ready is versus chip_good. > +{ > + struct cfi_private *cfi = map->fldrv_priv; > + > + return cfi->mfr == CFI_MFR_AMD && cfi->id == 0x0c01; > +} > + > +static int __xipram chip_good_for_write(struct map_info *map, > + struct flchip *chip, unsigned long addr, > + map_word expected) > +{ > + if (cfi_use_chip_ready_for_write(map)) > + return chip_ready(map, chip, addr); If possible and not too invasive I would definitely add a "quirks" flag somewhere instead of this cfi_use_chip_ready_for_write() check. Anyway, I would move this to the chip_good() implementation directly so we partially hide the quirks complexity from the core. > + > + return chip_good(map, chip, addr, expected); > +} > + > static int get_chip(struct map_info *map, struct flchip *chip, unsigned long adr, int mode) > { > DECLARE_WAITQUEUE(wait, current); > @@ -1686,7 +1703,7 @@ static int __xipram do_write_oneword_once(struct map_info *map, > * "chip_good" to avoid the failure due to scheduling. > */ > if (time_after(jiffies, timeo) && > - !chip_good(map, chip, adr, datum)) { > + !chip_good_for_write(map, chip, adr, datum)) { > xip_enable(map, chip, adr); > printk(KERN_WARNING "MTD %s(): software timeout\n", __func__); > xip_disable(map, chip, adr); > @@ -1694,7 +1711,7 @@ static int __xipram do_write_oneword_once(struct map_info *map, > break; > } > > - if (chip_good(map, chip, adr, datum)) { > + if (chip_good_for_write(map, chip, adr, datum)) { > if (cfi_check_err_status(map, chip, adr)) > ret = -EIO; > break; > @@ -1966,14 +1983,14 @@ static int __xipram do_write_buffer_wait(struct map_info *map, > * "chip_good" to avoid the failure due to scheduling. > */ > if (time_after(jiffies, timeo) && > - !chip_good(map, chip, adr, datum)) { > + !chip_good_for_write(map, chip, adr, datum)) { > pr_err("MTD %s(): software timeout, address:0x%.8lx.\n", > __func__, adr); > ret = -EIO; > break; > } > > - if (chip_good(map, chip, adr, datum)) { > + if (chip_good_for_write(map, chip, adr, datum)) { > if (cfi_check_err_status(map, chip, adr)) > ret = -EIO; > break; Thanks, Miquèl
