regmap: Ensure regmap_register_patch() is compatible with fast_io
With fast_io we use mutexes to lock the I/O operations so we would need
to do GFP_ATOMIC allocations if we wanted to do allocations inside the
lock as we do currently. Since it is unlikely that we will want to register
a patch outside of init where concurrency shouldn't be an issue move the
allocation of the patch data outside the lock.
Reported-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Mark Brown <broonie@linaro.org>
diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c
index 6a19515..e5a5509 100644
--- a/drivers/base/regmap/regmap.c
+++ b/drivers/base/regmap/regmap.c
@@ -2173,6 +2173,9 @@
* apply them immediately. Typically this is used to apply
* corrections to be applied to the device defaults on startup, such
* as the updates some vendors provide to undocumented registers.
+ *
+ * The caller must ensure that this function cannot be called
+ * concurrently with either itself or regcache_sync().
*/
int regmap_register_patch(struct regmap *map, const struct reg_default *regs,
int num_regs)
@@ -2185,6 +2188,17 @@
num_regs))
return 0;
+ p = krealloc(map->patch,
+ sizeof(struct reg_default) * (map->patch_regs + num_regs),
+ GFP_KERNEL);
+ if (p) {
+ memcpy(p + map->patch_regs, regs, num_regs * sizeof(*regs));
+ map->patch = p;
+ map->patch_regs += num_regs;
+ } else {
+ return -ENOMEM;
+ }
+
map->lock(map->lock_arg);
bypass = map->cache_bypass;
@@ -2202,17 +2216,6 @@
}
}
- p = krealloc(map->patch,
- sizeof(struct reg_default) * (map->patch_regs + num_regs),
- GFP_KERNEL);
- if (p) {
- memcpy(p + map->patch_regs, regs, num_regs * sizeof(*regs));
- map->patch = p;
- map->patch_regs += num_regs;
- } else {
- ret = -ENOMEM;
- }
-
out:
map->async = false;
map->cache_bypass = bypass;