[PATCH AUTOSEL 4.4 1/4] bus: sunxi-rsb: Return correct data when mixing 16-bit and 8-bit reads

[PATCH AUTOSEL 4.4 1/4] bus: sunxi-rsb: Return correct data when mixing 16-bit and 8-bit reads

[Sasha Levin]

From: Ondrej Jirman <megous@megous.com>

[ 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>
---
 drivers/bus/sunxi-rsb.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/bus/sunxi-rsb.c b/drivers/bus/sunxi-rsb.c
index 0ffb247b42d65..d45f48de42a0c 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);
-- 
2.20.1


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[PATCH AUTOSEL 4.4 4/4] i2c: st: fix missing struct parameter description

[Sasha Levin]

From: Alain Volmat <avolmat@me.com>

[ Upstream commit f491c6687332920e296d0209e366fe2ca7eab1c6 ]

Fix a missing struct parameter description to allow
warning free W=1 compilation.

Signed-off-by: Alain Volmat <avolmat@me.com>
Reviewed-by: Patrice Chotard <patrice.chotard@st.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/i2c/busses/i2c-st.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/i2c/busses/i2c-st.c b/drivers/i2c/busses/i2c-st.c
index 25020ec777c97..ee0a7d3dd0c65 100644
--- a/drivers/i2c/busses/i2c-st.c
+++ b/drivers/i2c/busses/i2c-st.c
@@ -399,6 +399,7 @@ static void st_i2c_wr_fill_tx_fifo(struct st_i2c_dev *i2c_dev)
 /**
  * st_i2c_rd_fill_tx_fifo() - Fill the Tx FIFO in read mode
  * @i2c_dev: Controller's private data
+ * @max: Maximum amount of data to fill into the Tx FIFO
  *
  * This functions fills the Tx FIFO with fixed pattern when
  * in read mode to trigger clock.
-- 
2.20.1


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