[PATCH 3.16.y-ckt 003/135] clocksource: exynos_mct: Fix bitmask regression for exynos4_mct_write

Luis Henriques luis.henriques at canonical.com
Fri Feb 6 11:59:41 UTC 2015


3.16.7-ckt6 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Tobias Jakobi <tjakobi at math.uni-bielefeld.de>

commit 8c38d28ba8da98f7102c31d35359b4dbe9d1f329 upstream.

EXYNOS4_MCT_L_MASK is defined as 0xffffff00, so applying this bitmask
produces a number outside the range 0x00 to 0xff, which always results
in execution of the default switch statement.

Obviously this is wrong and git history shows that the bitmask inversion
was incorrectly set during a refactoring of the MCT code.

Fix this by putting the inversion at the correct position again.

Acked-by: Kukjin Kim <kgene.kim at samsung.com>
Reported-by: GP Orcullo <kinsamanka at gmail.com>
Reviewed-by: Doug Anderson <dianders at chromium.org>
Signed-off-by: Tobias Jakobi <tjakobi at math.uni-bielefeld.de>
Signed-off-by: Daniel Lezcano <daniel.lezcano at linaro.org>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/clocksource/exynos_mct.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/clocksource/exynos_mct.c b/drivers/clocksource/exynos_mct.c
index ab51bf20a3ed..336a60fbabf9 100644
--- a/drivers/clocksource/exynos_mct.c
+++ b/drivers/clocksource/exynos_mct.c
@@ -97,8 +97,8 @@ static void exynos4_mct_write(unsigned int value, unsigned long offset)
 	__raw_writel(value, reg_base + offset);
 
 	if (likely(offset >= EXYNOS4_MCT_L_BASE(0))) {
-		stat_addr = (offset & ~EXYNOS4_MCT_L_MASK) + MCT_L_WSTAT_OFFSET;
-		switch (offset & EXYNOS4_MCT_L_MASK) {
+		stat_addr = (offset & EXYNOS4_MCT_L_MASK) + MCT_L_WSTAT_OFFSET;
+		switch (offset & ~EXYNOS4_MCT_L_MASK) {
 		case MCT_L_TCON_OFFSET:
 			mask = 1 << 3;		/* L_TCON write status */
 			break;
-- 
2.1.4





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