regmap: Fix for v6.7

One fix here, for an interaction between noinc registers and caches - if
 a device uses noinc registers (which is rare) then we could corrupt
 registers after the noinc register in the cache.
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Merge tag 'regmap-fix-v6.7-merge-window' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap

Pull regmap fix from Mark Brown:
 "One fix here, for an interaction between noinc registers and caches.

  If a device uses noinc registers (which is rare) then we could corrupt
  registers after the noinc register in the cache"

* tag 'regmap-fix-v6.7-merge-window' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap:
  regmap: prevent noinc writes from clobbering cache
This commit is contained in:
Linus Torvalds 2023-11-07 16:56:10 -08:00
commit eaec7c9892
1 changed files with 9 additions and 7 deletions

View File

@ -1620,17 +1620,19 @@ static int _regmap_raw_write_impl(struct regmap *map, unsigned int reg,
}
if (!map->cache_bypass && map->format.parse_val) {
unsigned int ival;
unsigned int ival, offset;
int val_bytes = map->format.val_bytes;
for (i = 0; i < val_len / val_bytes; i++) {
ival = map->format.parse_val(val + (i * val_bytes));
ret = regcache_write(map,
reg + regmap_get_offset(map, i),
ival);
/* Cache the last written value for noinc writes */
i = noinc ? val_len - val_bytes : 0;
for (; i < val_len; i += val_bytes) {
ival = map->format.parse_val(val + i);
offset = noinc ? 0 : regmap_get_offset(map, i / val_bytes);
ret = regcache_write(map, reg + offset, ival);
if (ret) {
dev_err(map->dev,
"Error in caching of register: %x ret: %d\n",
reg + regmap_get_offset(map, i), ret);
reg + offset, ret);
return ret;
}
}