ARM: SAMSUNG: fix race in s3c_adc_start for ADC

Checking for adc->ts_pend already claimed should be done with the
lock held.

Signed-off-by: Todd Poynor <toddpoynor@google.com>
Acked-by: Ben Dooks <ben-linux@fluff.org>
Cc: Stable <stable@vger.kernel.org>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>

1 files changed, 5 insertions, 3 deletions

diff --git a/arch/arm/plat-samsung/adc.c b/arch/arm/plat-samsung/adc.c
index 33ecd0c9f0c3..b1e05ccff3ac 100644
--- a/arch/arm/plat-samsung/adc.c
+++ b/arch/arm/plat-samsung/adc.c
@@ -157,11 +157,13 @@ int s3c_adc_start(struct s3c_adc_client *client,
                 return -EINVAL;
         }
 
-        if (client->is_ts && adc->ts_pend)
-                return -EAGAIN;
-
         spin_lock_irqsave(&adc->lock, flags);
 
+        if (client->is_ts && adc->ts_pend) {
+                spin_unlock_irqrestore(&adc->lock, flags);
+                return -EAGAIN;
+        }
+
         client->channel = channel;
         client->nr_samples = nr_samples;