* [PATCH V1] Fix Regmap Block Write single-rw Mutex Deadlock
@ 2013-10-09 16:44 Anthony Olech
2013-10-09 17:49 ` Mark Brown
0 siblings, 1 reply; 2+ messages in thread
From: Anthony Olech @ 2013-10-09 16:44 UTC (permalink / raw)
To: Mark Brown, Greg Kroah-Hartman; +Cc: LKML, David Dajun Chen
This patch is relative to linux-next repository tag next-20130927
When regmap_bulk_write() is called with the map->use_single_rw flag set
an immediate mutex deadlock happens because regmap_raw_write() is called
after obtaining the mutex and regmap_raw_write() itself then tries to
obtain the mutex as well.
It is obvious that no one other than myself tried it with a real device.
I did, but only for the purposes of an experiment and demonstration.
But even if this situation will never ever happen with a real device, it
is a bug and therefore should be fixed.
Signed-off-by: Anthony Olech <anthony.olech.opensource@diasemi.com>
---
drivers/base/regmap/regmap.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)
diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c
index 00152bf..6bd9294 100644
--- a/drivers/base/regmap/regmap.c
+++ b/drivers/base/regmap/regmap.c
@@ -1488,10 +1488,11 @@ int regmap_bulk_write(struct regmap *map, unsigned int reg, const void *val,
*/
if (map->use_single_rw) {
for (i = 0; i < val_count; i++) {
- ret = regmap_raw_write(map,
- reg + (i * map->reg_stride),
- val + (i * val_bytes),
- val_bytes);
+ ret = _regmap_raw_write(map,
+ reg + (i * map->reg_stride),
+ val + (i * val_bytes),
+ val_bytes,
+ false);
if (ret != 0)
return ret;
}
--
end-of-patch for Fix Regmap Block Write single-rw Mutex Deadlock V1
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH V1] Fix Regmap Block Write single-rw Mutex Deadlock
2013-10-09 16:44 [PATCH V1] Fix Regmap Block Write single-rw Mutex Deadlock Anthony Olech
@ 2013-10-09 17:49 ` Mark Brown
0 siblings, 0 replies; 2+ messages in thread
From: Mark Brown @ 2013-10-09 17:49 UTC (permalink / raw)
To: Anthony Olech; +Cc: Greg Kroah-Hartman, LKML, David Dajun Chen
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On Wed, Oct 09, 2013 at 05:44:38PM +0100, Anthony Olech wrote:
Applied, thanks. Please format your patches as covered in
SubmittingPatches - use subjects appropriate to the subsystem and keep
noise like the above after the ---. I've fixed these and the strange
capitalisation when applying.
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