From: Todd Poynor <toddpoynor@google.com>
Date: Fri, 13 Jul 2012 06:30:48 +0000 (+0900)
Subject: ARM: SAMSUNG: fix race in s3c_adc_start for ADC
X-Git-Tag: firefly_0821_release~7541^2~948
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=64428b015e0bba23744e2a64a011be9738d05356;p=firefly-linux-kernel-4.4.55.git

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 e8f2be2d67f2..df14954aa1cc 100644
--- 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;