[PATCH v2 1/1] mtd: cfi_cmdset_0001: Factor out do_write_buffer_locked() to reduce stack frame

Andy Shevchenko
2026-02-04T01:26:36Z

Compiler is not happy about used stack frame:

drivers/mtd/chips/cfi_cmdset_0001.c: In function 'do_write_buffer':
drivers/mtd/chips/cfi_cmdset_0001.c:1887:1: error: the frame size of 1296 bytes is larger than 1280 bytes [-Werror=frame-larger-than=]

Fix this by factoring out do_write_buffer_locked().

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
v2: kept DIS/ENABLE_VPP paired
drivers/mtd/chips/cfi_cmdset_0001.c | 82 +++++++++++++++++------------
1 file changed, 48 insertions(+), 34 deletions(-)

diff --git a/drivers/mtd/chips/cfi_cmdset_0001.c b/drivers/mtd/chips/cfi_cmdset_0001.c
index c10693ba265b..c495bee04053 100644
--- a/drivers/mtd/chips/cfi_cmdset_0001.c
+++ b/drivers/mtd/chips/cfi_cmdset_0001.c
@@ -1720,42 +1720,24 @@ static int cfi_intelext_write_words (struct mtd_info *mtd, loff_t to , size_t le
}

-static int __xipram do_write_buffer(struct map_info *map, struct flchip *chip,
- unsigned long adr, const struct kvec **pvec,
- unsigned long *pvec_seek, int len)
+static int __xipram do_write_buffer_locked(struct map_info *map, struct flchip *chip,
+ unsigned long cmd_adr, unsigned long adr,
+ const struct kvec **pvec,
+ unsigned long *pvec_seek, int len)
{
struct cfi_private *cfi = map->fldrv_priv;
map_word status, write_cmd, datum;
- unsigned long cmd_adr;
- int ret, wbufsize, word_gap, words;
+ int ret, word_gap, words;
const struct kvec *vec;
unsigned long vec_seek;
unsigned long initial_adr;
int initial_len = len;

- wbufsize = cfi_interleave(cfi) << cfi->cfiq->MaxBufWriteSize;
- adr += chip->start;
initial_adr = adr;
- cmd_adr = adr & ~(wbufsize-1);
-
- /* Sharp LH28F640BF chips need the first address for the
- * Page Buffer Program command. See Table 5 of
- * LH28F320BF, LH28F640BF, LH28F128BF Series (Appendix FUM00701) */
- if (is_LH28F640BF(cfi))
- cmd_adr = adr;

/* Let's determine this according to the interleave only once */
Mwrite_cmd = (cfi->cfiq->P_ID != P_ID_INTEL_PERFORMANCE) ? CMD(0xe8) : CMD(0xe9);

- mutex_lock(&chip->mutex);
- ret = get_chip(map, chip, cmd_adr, FL_WRITING);
- if (ret) {
- mutex_unlock(&chip->mutex);
- return ret;
- }
-
- XIP_INVAL_CACHED_RANGE(map, initial_adr, initial_len);
- ENABLE_VPP(map);
xip_disable(map, chip, cmd_adr);

/* §4.8 of the 28FxxxJ3A datasheet says "Any time SR.4 and/or SR.5 is set
@@ -1789,7 +1771,7 @@ static int __xipram do_write_buffer(struct map_info *map, struct flchip *chip,
xip_enable(map, chip, cmd_adr);
printk(KERN_ERR "%s: Chip not ready for buffer write. Xstatus = %lx, status = %lx\n",
map->name, Xstatus.x[0], status.x[0]);
- goto out;
+ return ret;
}

/* Figure out the number of words to write */
@@ -1853,7 +1835,7 @@ static int __xipram do_write_buffer(struct map_info *map, struct flchip *chip,
chip->state = FL_STATUS;
xip_enable(map, chip, cmd_adr);
printk(KERN_ERR "%s: buffer write error (status timeout)\n", map->name);
- goto out;
+ return ret;
}

/* check for errors */
@@ -1866,21 +1848,53 @@ static int __xipram do_write_buffer(struct map_info *map, struct flchip *chip,
map_write(map, CMD(0x70), cmd_adr);
xip_enable(map, chip, cmd_adr);

- if (chipstatus & 0x02) {
- ret = -EROFS;
- } else if (chipstatus & 0x08) {
+ if (chipstatus & 0x02)
+ return -EROFS;
+
+ if (chipstatus & 0x08) {
printk(KERN_ERR "%s: buffer write error (bad VPP)\n", map->name);
- ret = -EIO;
- } else {
- printk(KERN_ERR "%s: buffer write error (status 0x%lx)\n", map->name, chipstatus);
- ret = -EINVAL;
+ return -EIO;
}

- goto out;
+ printk(KERN_ERR "%s: buffer write error (status 0x%lx)\n", map->name, chipstatus);
+ return -EINVAL;
}

xip_enable(map, chip, cmd_adr);
- out: DISABLE_VPP(map);
+ return 0;
+}
+
+static int __xipram do_write_buffer(struct map_info *map, struct flchip *chip,
+ unsigned long adr, const struct kvec **pvec,
+ unsigned long *pvec_seek, int len)
+{
+ struct cfi_private *cfi = map->fldrv_priv;
+ unsigned long cmd_adr;
+ int ret, wbufsize;
+
+ wbufsize = cfi_interleave(cfi) << cfi->cfiq->MaxBufWriteSize;
+ adr += chip->start;
+ cmd_adr = adr & ~(wbufsize - 1);
+
+ /* Sharp LH28F640BF chips need the first address for the
+ * Page Buffer Program command. See Table 5 of
+ * LH28F320BF, LH28F640BF, LH28F128BF Series (Appendix FUM00701) */
+ if (is_LH28F640BF(cfi))
+ cmd_adr = adr;
+
+ mutex_lock(&chip->mutex);
+ ret = get_chip(map, chip, cmd_adr, FL_WRITING);
+ if (ret) {
+ mutex_unlock(&chip->mutex);
+ return ret;
+ }
+
+ XIP_INVAL_CACHED_RANGE(map, adr, len);
+ ENABLE_VPP(map);
+
+ ret = do_write_buffer_locked(map, chip, cmd_adr, adr, pvec, pvec_seek, len);
+
+ DISABLE_VPP(map);
put_chip(map, chip, cmd_adr);
mutex_unlock(&chip->mutex);
return ret;
--
2.50.1