diff options
| author | Ondrej Jirman <megous@megous.com> | 2020-02-21 21:27:26 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-04-24 07:58:46 +0200 |
| commit | b41174d9214db1451b1137288e3051317f647bf1 (patch) | |
| tree | f551cf964514e6ad387c606be5cca74749560afd /drivers | |
| parent | 5188957a315f664d46ff58fedecbc0f7503f1b22 (diff) | |
bus: sunxi-rsb: Return correct data when mixing 16-bit and 8-bit reads
[ Upstream commit a43ab30dcd4a1abcdd0d2461bf1cf7c0817f6cd3 ]
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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/bus/sunxi-rsb.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/bus/sunxi-rsb.c b/drivers/bus/sunxi-rsb.c index 2051d926e303..4f3d988210b0 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); |