ARM: SAMSUNG: fix race in s3c_adc_start for ADC

commit 8265981bb439f3ecc5356fb877a6c2a6636ac88a upstream.

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>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/arm/plat-samsung/adc.c b/arch/arm/plat-samsung/adc.c
index e8f2be2d67f2cac33961487b47a7880b68f33832..df14954aa1cce6d09f682554c3fee5909d81b481 100644 (file)
--- a/arch/arm/plat-samsung/adc.c
+++ b/arch/arm/plat-samsung/adc.c
@@ -143,11 +143,13 @@ 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;