Re: [PATCH] mtd: cfi_cmdset_0002: Use chip_ready() for write on S29GL064N

Hi,

Thanks  for your review and comments.

On 2022/03/01 0:34, Vignesh Raghavendra wrote:

Hi,

On 14/02/22 11:50 pm, Tokunori Ikegami wrote:

...

The regression issue has been caused on S29GL064N and reported it. Also the change mentioned is to use chip_good() for buffered write. So disable the change on S29GL064N and use chip_ready() as before.

Fixes: dfeae1073583("mtd: cfi_cmdset_0002: Change write buffer to check correct value") Signed-off-by: Tokunori Ikegami ikegami.t@gmail.com Tested-by: Ahmad Fatoum a.fatoum@pengutronix.de Cc: linux-mtd@lists.infradead.org Cc: stable@vger.kernel.org

---

Thanks for working on the fix.

Please CC maintainers from

./scripts/get_maintainer.pl -f drivers/mtd/chips/cfi_cmdset_0002.c

Else, patch would not get attention in time.

Just added the maintainers as CC by the version 2 patch.

...

drivers/mtd/chips/cfi_cmdset_0002.c | 105 ++++++++++++++++------------ 1 file changed, 59 insertions(+), 46 deletions(-)

diff --git a/drivers/mtd/chips/cfi_cmdset_0002.c b/drivers/mtd/chips/cfi_cmdset_0002.c index a761134fd3be..a0dfc8ace899 100644 --- a/drivers/mtd/chips/cfi_cmdset_0002.c +++ b/drivers/mtd/chips/cfi_cmdset_0002.c @@ -48,6 +48,7 @@ #define SST49LF040B 0x0050 #define SST49LF008A 0x005a #define AT49BV6416 0x00d6 +#define S29GL064N_MN12 0x0c01 /*

• Status Register bit description. Used by flash devices that don't

@@ -109,6 +110,8 @@ static struct mtd_chip_driver cfi_amdstd_chipdrv = { .module = THIS_MODULE }; +static bool use_chip_good_for_write;

Can we use per device private flag? Else this wont work on systems with multiple CFI flashes with one of them being S29GL064N_MN12.

Yes fixed the patch to check the cfi mfr and id values directly instead of the static variable.

...

/*

• Use status register to poll for Erase/write completion when DQ is not
• supported. This is indicated by Bit[1:0] of SoftwareFeatures field in

@@ -283,6 +286,17 @@ static void fixup_use_write_buffers(struct mtd_info *mtd) } #endif /* !FORCE_WORD_WRITE */ +static void fixup_use_chip_good_for_write(struct mtd_info *mtd) +{

• struct map_info *map = mtd->priv;
• struct cfi_private *cfi = map->fldrv_priv;
• if (cfi->mfr == CFI_MFR_AMD && cfi->id == S29GL064N_MN12)

• return;
  

• use_chip_good_for_write = true;

+}

• /* Atmel chips don't use the same PRI format as AMD chips */ static void fixup_convert_atmel_pri(struct mtd_info *mtd) {

@@ -462,7 +476,7 @@ static struct cfi_fixup cfi_fixup_table[] = { { CFI_MFR_AMD, 0x0056, fixup_use_secsi }, { CFI_MFR_AMD, 0x005C, fixup_use_secsi }, { CFI_MFR_AMD, 0x005F, fixup_use_secsi },

• { CFI_MFR_AMD, 0x0c01, fixup_s29gl064n_sectors },

• { CFI_MFR_AMD, S29GL064N_MN12, fixup_s29gl064n_sectors }, { CFI_MFR_AMD, 0x1301, fixup_s29gl064n_sectors }, { CFI_MFR_AMD, 0x1a00, fixup_s29gl032n_sectors }, { CFI_MFR_AMD, 0x1a01, fixup_s29gl032n_sectors },

@@ -474,6 +488,7 @@ static struct cfi_fixup cfi_fixup_table[] = { #if !FORCE_WORD_WRITE { CFI_MFR_ANY, CFI_ID_ANY, fixup_use_write_buffers }, #endif

• { CFI_MFR_ANY, CFI_ID_ANY, fixup_use_chip_good_for_write }, { 0, 0, NULL } }; static struct cfi_fixup jedec_fixup_table[] = {

@@ -801,42 +816,61 @@ static struct mtd_info *cfi_amdstd_setup(struct mtd_info *mtd) return NULL; } -/*

• • Return true if the chip is ready.
• • Ready is one of: read mode, query mode, erase-suspend-read mode (in any
• • non-suspended sector) and is indicated by no toggle bits toggling.
• • Note that anything more complicated than checking if no bits are toggling
• • (including checking DQ5 for an error status) is tricky to get working
• • correctly and is therefore not done (particularly with interleaved chips
• • as each chip must be checked independently of the others).
• */

-static int __xipram chip_ready(struct map_info *map, struct flchip *chip,

• 	       unsigned long addr)
  

+static int __xipram chip_check(struct map_info *map, struct flchip *chip,

• 	       unsigned long addr, map_word *expected)
  

  { struct cfi_private *cfi = map->fldrv_priv;

• map_word d, t;

• map_word oldd, curd;
• int ret;

if (cfi_use_status_reg(cfi)) { map_word ready = CMD(CFI_SR_DRB);

Unrelated change?

Yes deleted the empty line added.

...

/*
 * For chips that support status register, check device
 * ready bit
 */
cfi_send_gen_cmd(0x70, cfi->addr_unlock1, chip->start, map, cfi,
		 cfi->device_type, NULL);

• d = map_read(map, addr);
  

• curd = map_read(map, addr);
  

• return map_word_andequal(map, d, ready, ready);
  

• return map_word_andequal(map, curd, ready, ready);
  

  }

• d = map_read(map, addr);
• t = map_read(map, addr);

• oldd = map_read(map, addr);
• curd = map_read(map, addr);
• ret = map_word_equal(map, oldd, curd);
• if (!ret || !expected)

• return ret;
  

Why even read oldd and curd if !expected ?

Since required this for chip ready that checks the oldd and curd if equal or not.

Regards, Ikegami

...

• return map_word_equal(map, curd, *expected);

+}

+static int __xipram chip_good_for_write(struct map_info *map,

• 			struct flchip *chip, unsigned long addr,
  

• 			map_word expected)
  

+{

• if (use_chip_good_for_write)

• return chip_check(map, chip, addr, &expected);
  

• return map_word_equal(map, d, t);

• return chip_check(map, chip, addr, NULL); }

+/*

• • Return true if the chip is ready.
• • Ready is one of: read mode, query mode, erase-suspend-read mode (in any
• • non-suspended sector) and is indicated by no toggle bits toggling.
• • Note that anything more complicated than checking if no bits are toggling
• • (including checking DQ5 for an error status) is tricky to get working
• • correctly and is therefore not done (particularly with interleaved chips
• • as each chip must be checked independently of the others).
• */

+#define chip_ready(map, chip, addr) chip_check(map, chip, addr, NULL)

• /*
  • Return true if the chip is ready and has the correct value.

@@ -855,28 +889,7 @@ static int __xipram chip_ready(struct map_info *map, struct flchip *chip, static int __xipram chip_good(struct map_info *map, struct flchip *chip, unsigned long addr, map_word expected) {

• struct cfi_private *cfi = map->fldrv_priv;
• map_word oldd, curd;
• if (cfi_use_status_reg(cfi)) {

• map_word ready = CMD(CFI_SR_DRB);
  

• /*
  

•  * For chips that support status register, check device
  

•  * ready bit
  

•  */
  

• cfi_send_gen_cmd(0x70, cfi->addr_unlock1, chip->start, map, cfi,
  

• 		 cfi->device_type, NULL);
  

• curd = map_read(map, addr);
  

• return map_word_andequal(map, curd, ready, ready);
  

• }
• oldd = map_read(map, addr);
• curd = map_read(map, addr);
• return map_word_equal(map, oldd, curd) &&

• map_word_equal(map, curd, expected);
  

• return chip_check(map, chip, addr, &expected); }

static int get_chip(struct map_info *map, struct flchip *chip, unsigned long adr, int mode) @@ -1699,7 +1712,7 @@ 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);
  

@@ -1707,7 +1720,7 @@ 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;
  

@@ -1979,14 +1992,14 @@ 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;