regmap: Ensure regmap_register_patch() is compatible with fast_io

From: Mark Brown <[email protected]>

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 <[email protected]>

Signed-off-by Mark Brown <[email protected]>

---
 drivers/base/regmap/regmap.c | 25 ++++++++++++++-----------
 1 file changed, 14 insertions(+), 11 deletions(-)

drivers/base/regmap/regmap.c +4 -0

index 554119535a64..2d7d55b3bedb 100644
@@ -2396,6 +2396,9 @@ EXPORT_SYMBOL_GPL(regmap_async_complete);
  * 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)

@@ -2408,6 +2411,17 @@ int regmap_register_patch(struct regmap *map, const struct reg_default *regs,
            num_regs))
                return 0;
 
+       p = krealloc(map->patch,

[...]

2014-03-18 13:02 GMT+01:00 Mark Brown <[email protected]>:

drivers/base/regmap/regmap.c int regmap_register_patch(struct regmap *map, const struct reg_default *regs, · line 2424

Quoted 8 lines

drivers/base/regmap/regmap.c +8 -0

+       if (p) {
+               memcpy(p + map->patch_regs, regs, num_regs * sizeof(*regs));
+               map->patch = p;
+               map->patch_regs += num_regs;
+       } else {
+               return -ENOMEM;
+       }
+

I think that is not checkpatch-safe :-)