[PATCH AUTOSEL 4.4 05/12] i2c: i801: Don't silently correct invalid transfer size

[PATCH AUTOSEL 4.4 05/12] i2c: i801: Don't silently correct invalid transfer size

[Sasha Levin]

From: Heiner Kallweit <hkallweit1@gmail.com>

[ Upstream commit effa453168a7eeb8a562ff4edc1dbf9067360a61 ]

If an invalid block size is provided, reject it instead of silently
changing it to a supported value. Especially critical I see the case of
a write transfer with block length 0. In this case we have no guarantee
that the byte we would write is valid. When silently reducing a read to
32 bytes then we don't return an error and the caller may falsely
assume that we returned the full requested data.

If this change should break any (broken) caller, then I think we should
fix the caller.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/i2c/busses/i2c-i801.c | 15 +++++----------
 1 file changed, 5 insertions(+), 10 deletions(-)

diff --git a/drivers/i2c/busses/i2c-i801.c b/drivers/i2c/busses/i2c-i801.c
index 4399016a6caba..73026c00220c2 100644
--- a/drivers/i2c/busses/i2c-i801.c
+++ b/drivers/i2c/busses/i2c-i801.c
@@ -669,6 +669,11 @@ static int i801_block_transaction(struct i801_priv *priv,
 	int result = 0;
 	unsigned char hostc;
 
+	if (read_write == I2C_SMBUS_READ && command == I2C_SMBUS_BLOCK_DATA)
+		data->block[0] = I2C_SMBUS_BLOCK_MAX;
+	else if (data->block[0] < 1 || data->block[0] > I2C_SMBUS_BLOCK_MAX)
+		return -EPROTO;
+
 	if (command == I2C_SMBUS_I2C_BLOCK_DATA) {
 		if (read_write == I2C_SMBUS_WRITE) {
 			/* set I2C_EN bit in configuration register */
@@ -682,16 +687,6 @@ static int i801_block_transaction(struct i801_priv *priv,
 		}
 	}
 
-	if (read_write == I2C_SMBUS_WRITE
-	 || command == I2C_SMBUS_I2C_BLOCK_DATA) {
-		if (data->block[0] < 1)
-			data->block[0] = 1;
-		if (data->block[0] > I2C_SMBUS_BLOCK_MAX)
-			data->block[0] = I2C_SMBUS_BLOCK_MAX;
-	} else {
-		data->block[0] = 32;	/* max for SMBus block reads */
-	}
-
 	/* Experience has shown that the block buffer can only be used for
 	   SMBus (not I2C) block transactions, even though the datasheet
 	   doesn't mention this limitation. */
-- 
2.34.1

[PATCH AUTOSEL 4.4 07/12] i2c: mpc: Correct I2C reset procedure

[Sasha Levin]

From: Joakim Tjernlund <joakim.tjernlund@infinera.com>

[ Upstream commit ebe82cf92cd4825c3029434cabfcd2f1780e64be ]

Current I2C reset procedure is broken in two ways:
1) It only generate 1 START instead of 9 STARTs and STOP.
2) It leaves the bus Busy so every I2C xfer after the first
   fixup calls the reset routine again, for every xfer there after.

This fixes both errors.

Signed-off-by: Joakim Tjernlund <joakim.tjernlund@infinera.com>
Acked-by: Scott Wood <oss@buserror.net>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/i2c/busses/i2c-mpc.c | 23 +++++++++++++++--------
 1 file changed, 15 insertions(+), 8 deletions(-)

diff --git a/drivers/i2c/busses/i2c-mpc.c b/drivers/i2c/busses/i2c-mpc.c
index 2e083a71c2215..988ea9df6654c 100644
--- a/drivers/i2c/busses/i2c-mpc.c
+++ b/drivers/i2c/busses/i2c-mpc.c
@@ -107,23 +107,30 @@ static irqreturn_t mpc_i2c_isr(int irq, void *dev_id)
 /* Sometimes 9th clock pulse isn't generated, and slave doesn't release
  * the bus, because it wants to send ACK.
  * Following sequence of enabling/disabling and sending start/stop generates
- * the 9 pulses, so it's all OK.
+ * the 9 pulses, each with a START then ending with STOP, so it's all OK.
  */
 static void mpc_i2c_fixup(struct mpc_i2c *i2c)
 {
 	int k;
-	u32 delay_val = 1000000 / i2c->real_clk + 1;
-
-	if (delay_val < 2)
-		delay_val = 2;
+	unsigned long flags;
 
 	for (k = 9; k; k--) {
 		writeccr(i2c, 0);
-		writeccr(i2c, CCR_MSTA | CCR_MTX | CCR_MEN);
+		writeb(0, i2c->base + MPC_I2C_SR); /* clear any status bits */
+		writeccr(i2c, CCR_MEN | CCR_MSTA); /* START */
+		readb(i2c->base + MPC_I2C_DR); /* init xfer */
+		udelay(15); /* let it hit the bus */
+		local_irq_save(flags); /* should not be delayed further */
+		writeccr(i2c, CCR_MEN | CCR_MSTA | CCR_RSTA); /* delay SDA */
 		readb(i2c->base + MPC_I2C_DR);
-		writeccr(i2c, CCR_MEN);
-		udelay(delay_val << 1);
+		if (k != 1)
+			udelay(5);
+		local_irq_restore(flags);
 	}
+	writeccr(i2c, CCR_MEN); /* Initiate STOP */
+	readb(i2c->base + MPC_I2C_DR);
+	udelay(15); /* Let STOP propagate */
+	writeccr(i2c, 0);
 }
 
 static int i2c_wait(struct mpc_i2c *i2c, unsigned timeout, int writing)
-- 
2.34.1

[PATCH AUTOSEL 4.4 10/12] i2c: designware-pci: Fix to change data types of hcnt and lcnt parameters

[Sasha Levin]

From: Lakshmi Sowjanya D <lakshmi.sowjanya.d@intel.com>

[ Upstream commit d52097010078c1844348dc0e467305e5f90fd317 ]

The data type of hcnt and lcnt in the struct dw_i2c_dev is of type u16.
It's better to have same data type in struct dw_scl_sda_cfg as well.

Reported-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Lakshmi Sowjanya D <lakshmi.sowjanya.d@intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/i2c/busses/i2c-designware-pcidrv.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/i2c/busses/i2c-designware-pcidrv.c b/drivers/i2c/busses/i2c-designware-pcidrv.c
index 1543d35d228df..6831883741215 100644
--- a/drivers/i2c/busses/i2c-designware-pcidrv.c
+++ b/drivers/i2c/busses/i2c-designware-pcidrv.c
@@ -53,10 +53,10 @@ enum dw_pci_ctl_id_t {
 };
 
 struct dw_scl_sda_cfg {
-	u32 ss_hcnt;
-	u32 fs_hcnt;
-	u32 ss_lcnt;
-	u32 fs_lcnt;
+	u16 ss_hcnt;
+	u16 fs_hcnt;
+	u16 ss_lcnt;
+	u16 fs_lcnt;
 	u32 sda_hold;
 };
 
-- 
2.34.1