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authorOndrej Jirman <megous@megous.com>2020-02-21 23:27:26 +0300
committerMaxime Ripard <maxime@cerno.tech>2020-02-24 14:02:38 +0300
commita43ab30dcd4a1abcdd0d2461bf1cf7c0817f6cd3 (patch)
tree3134b5c4c3753d90084ce9448050747d83c3e2c8 /drivers/bus/sunxi-rsb.c
parentb642d4825441bf30c72b72deb739bd2d5f53af08 (diff)
downloadlinux-a43ab30dcd4a1abcdd0d2461bf1cf7c0817f6cd3.tar.xz
bus: sunxi-rsb: Return correct data when mixing 16-bit and 8-bit reads
When doing a 16-bit read that returns data in the MSB byte, the RSB_DATA register will keep the MSB byte unchanged when doing the following 8-bit read. sunxi_rsb_read() will then return a result that contains high byte from 16-bit read mixed with the 8-bit result. The consequence is that after this happens the PMIC's regmap will look like this: (0x33 is the high byte from the 16-bit read) % cat /sys/kernel/debug/regmap/sunxi-rsb-3a3/registers 00: 33 01: 33 02: 33 03: 33 04: 33 05: 33 06: 33 07: 33 08: 33 09: 33 0a: 33 0b: 33 0c: 33 0d: 33 0e: 33 [snip] Fix this by masking the result of the read with the correct mask based on the size of the read. There are no 16-bit users in the mainline kernel, so this doesn't need to get into the stable tree. Signed-off-by: Ondrej Jirman <megous@megous.com> Acked-by: Chen-Yu Tsai <wens@csie.org> Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Diffstat (limited to 'drivers/bus/sunxi-rsb.c')
-rw-r--r--drivers/bus/sunxi-rsb.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/bus/sunxi-rsb.c b/drivers/bus/sunxi-rsb.c
index be79d6c6a4e4..1bb00a959c67 100644
--- a/drivers/bus/sunxi-rsb.c
+++ b/drivers/bus/sunxi-rsb.c
@@ -345,7 +345,7 @@ static int sunxi_rsb_read(struct sunxi_rsb *rsb, u8 rtaddr, u8 addr,
if (ret)
goto unlock;
- *buf = readl(rsb->regs + RSB_DATA);
+ *buf = readl(rsb->regs + RSB_DATA) & GENMASK(len * 8 - 1, 0);
unlock:
mutex_unlock(&rsb->lock);