[PATCH 5.4 195/222] mtd: cfi_cmdset_0002: fix delayed error detection on HyperFlash

Greg Kroah-Hartman
2020-01-22T13:28:53Z

From: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>

commit c15995695ea971253ea9507f6732c8cd35384e01 upstream.

The commit 4844ef80305d ("mtd: cfi_cmdset_0002: Add support for polling
status register") added checking for the status register error bits into
chip_good() to only return 1 if these bits are 0s. Unfortunately, this
means that polling using chip_good() always reaches a timeout condition
when erase or program failure bits are set. Let's fully delegate the task
of determining the error conditions to cfi_check_err_status() and make
chip_good() only look for the Device Ready/Busy condition.

Fixes: 4844ef80305d ("mtd: cfi_cmdset_0002: Add support for polling status register")
Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/mtd/chips/cfi_cmdset_0002.c | 58 ++++++++++++++++++++----------------
1 file changed, 33 insertions(+), 25 deletions(-)

--- a/drivers/mtd/chips/cfi_cmdset_0002.c
+++ b/drivers/mtd/chips/cfi_cmdset_0002.c
@@ -123,14 +123,14 @@ static int cfi_use_status_reg(struct cfi
(extp->SoftwareFeatures & poll_mask) == CFI_POLL_STATUS_REG;
}

-static void cfi_check_err_status(struct map_info *map, struct flchip *chip,
- unsigned long adr)
+static int cfi_check_err_status(struct map_info *map, struct flchip *chip,
+ unsigned long adr)
{
struct cfi_private *cfi = map->fldrv_priv;
map_word status;

if (!cfi_use_status_reg(cfi))
- return;
+ return 0;

cfi_send_gen_cmd(0x70, cfi->addr_unlock1, chip->start, map, cfi,
cfi->device_type, NULL);
@@ -138,7 +138,7 @@ static void cfi_check_err_status(struct

/* The error bits are invalid while the chip's busy */
if (!map_word_bitsset(map, status, CMD(CFI_SR_DRB)))
- return;
+ return 0;

if (map_word_bitsset(map, status, CMD(0x3a))) {
unsigned long chipstatus = MERGESTATUS(status);
@@ -155,7 +155,12 @@ static void cfi_check_err_status(struct
if (chipstatus & CFI_SR_SLSB)
pr_err("%s sector write protected, status %lx\n",
map->name, chipstatus);
+
+ /* Erase/Program status bits are set on the operation failure */
+ if (chipstatus & (CFI_SR_ESB | CFI_SR_PSB))
+ return 1;
}
+ return 0;
}

/* #define DEBUG_CFI_FEATURES */
@@ -852,20 +857,16 @@ static int __xipram chip_good(struct map

if (cfi_use_status_reg(cfi)) {
map_word ready = CMD(CFI_SR_DRB);
- map_word err = CMD(CFI_SR_PSB | CFI_SR_ESB);
+
/*
* For chips that support status register, check device
- * ready bit and Erase/Program status bit to know if
- * operation succeeded.
+ * ready bit
*/
cfi_send_gen_cmd(0x70, cfi->addr_unlock1, chip->start, map, cfi,
cfi->device_type, NULL);
curd = map_read(map, addr);

- if (map_word_andequal(map, curd, ready, ready))
- return !map_word_bitsset(map, curd, err);
-
- return 0;
+ return map_word_andequal(map, curd, ready, ready);
}

oldd = map_read(map, addr);
@@ -1703,8 +1704,11 @@ static int __xipram do_write_oneword_onc
break;
}

- if (chip_good(map, chip, adr, datum))
+ if (chip_good(map, chip, adr, datum)) {
+ if (cfi_check_err_status(map, chip, adr))
+ ret = -EIO;
break;
+ }

/* Latency issues. Drop the lock, wait a while and retry */
UDELAY(map, chip, adr, 1);
@@ -1777,7 +1781,6 @@ static int __xipram do_write_oneword_ret
ret = do_write_oneword_once(map, chip, adr, datum, mode, cfi);
if (ret) {
/* reset on all failures. */
- cfi_check_err_status(map, chip, adr);
map_write(map, CMD(0xF0), chip->start);
/* FIXME - should have reset delay before continuing */

@@ -1974,12 +1977,17 @@ static int __xipram do_write_buffer_wait
*/
if (time_after(jiffies, timeo) &&
!chip_good(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(map, chip, adr, datum)) {
+ if (cfi_check_err_status(map, chip, adr))
+ ret = -EIO;
break;
+ }

/* Latency issues. Drop the lock, wait a while and retry */
UDELAY(map, chip, adr, 1);
@@ -2075,12 +2083,8 @@ static int __xipram do_write_buffer(stru
chip->word_write_time);

ret = do_write_buffer_wait(map, chip, adr, datum);
- if (ret) {
- cfi_check_err_status(map, chip, adr);
+ if (ret)
do_write_buffer_reset(map, chip, cfi);
- pr_err("MTD %s(): software timeout, address:0x%.8lx.\n",
- __func__, adr);
- }

xip_enable(map, chip, adr);

@@ -2275,9 +2279,9 @@ retry:
udelay(1);
}

- if (!chip_good(map, chip, adr, datum)) {
+ if (!chip_good(map, chip, adr, datum) ||
+ cfi_check_err_status(map, chip, adr)) {
/* reset on all failures. */
- cfi_check_err_status(map, chip, adr);
map_write(map, CMD(0xF0), chip->start);
/* FIXME - should have reset delay before continuing */

@@ -2471,8 +2475,11 @@ static int __xipram do_erase_chip(struct
chip->erase_suspended = 0;
}

- if (chip_good(map, chip, adr, map_word_ff(map)))
+ if (chip_good(map, chip, adr, map_word_ff(map))) {
+ if (cfi_check_err_status(map, chip, adr))
+ ret = -EIO;
break;
+ }

if (time_after(jiffies, timeo)) {
printk(KERN_WARNING "MTD %s(): software timeout\n",
@@ -2487,7 +2494,6 @@ static int __xipram do_erase_chip(struct
/* Did we succeed? */
if (ret) {
/* reset on all failures. */
- cfi_check_err_status(map, chip, adr);
map_write(map, CMD(0xF0), chip->start);
/* FIXME - should have reset delay before continuing */

@@ -2568,8 +2574,11 @@ static int __xipram do_erase_oneblock(st
chip->erase_suspended = 0;
}

- if (chip_good(map, chip, adr, map_word_ff(map)))
+ if (chip_good(map, chip, adr, map_word_ff(map))) {
+ if (cfi_check_err_status(map, chip, adr))
+ ret = -EIO;
break;
+ }

if (time_after(jiffies, timeo)) {
printk(KERN_WARNING "MTD %s(): software timeout\n",
@@ -2584,7 +2593,6 @@ static int __xipram do_erase_oneblock(st
/* Did we succeed? */
if (ret) {
/* reset on all failures. */
- cfi_check_err_status(map, chip, adr);
map_write(map, CMD(0xF0), chip->start);
/* FIXME - should have reset delay before continuing */