Revert "Merge branch 'mctp-i2c-driver'"

This reverts commit 71812af7234f30362b43ccff33f93890ae4c0655, reversing
changes made to cc0be1ad686fb29a4d127948486f40b17fb34b50.

Wolfram Sang says:

Please revert. Besides the driver in net, it modifies the I2C core
code. This has not been acked by the I2C maintainer (in this case me).
So, please don't pull this in via the net tree. The question raised here
(extending SMBus calls to 255 byte) is complicated because we need ABI
backwards compatibility.

Link: https://lore.kernel.org/all/YZJ9H4eM%2FM7OXVN0@shikoro/
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 7 insertions, 13 deletions

diff --git a/drivers/i2c/i2c-core-smbus.c b/drivers/i2c/i2c-core-smbus.c
index 743415584aba..e5b2d1465e7e 100644
--- a/drivers/i2c/i2c-core-smbus.c
+++ b/drivers/i2c/i2c-core-smbus.c
@@ -303,8 +303,7 @@ static void i2c_smbus_try_get_dmabuf(struct i2c_msg *msg, u8 init_val)
 	bool is_read = msg->flags & I2C_M_RD;
 	unsigned char *dma_buf;
 
-	dma_buf = kzalloc(I2C_SMBUS_V3_BLOCK_MAX + (is_read ? 2 : 3),
-		GFP_KERNEL);
+	dma_buf = kzalloc(I2C_SMBUS_BLOCK_MAX + (is_read ? 2 : 3), GFP_KERNEL);
 	if (!dma_buf)
 		return;
 
@@ -330,10 +329,9 @@ static s32 i2c_smbus_xfer_emulated(struct i2c_adapter *adapter, u16 addr,
 	 * initialize most things with sane defaults, to keep the code below
 	 * somewhat simpler.
 	 */
-	unsigned char msgbuf0[I2C_SMBUS_V3_BLOCK_MAX+3];
-	unsigned char msgbuf1[I2C_SMBUS_V3_BLOCK_MAX+2];
+	unsigned char msgbuf0[I2C_SMBUS_BLOCK_MAX+3];
+	unsigned char msgbuf1[I2C_SMBUS_BLOCK_MAX+2];
 	int nmsgs = read_write == I2C_SMBUS_READ ? 2 : 1;
-	u16 block_max;
 	u8 partial_pec = 0;
 	int status;
 	struct i2c_msg msg[2] = {
@@ -352,10 +350,6 @@ static s32 i2c_smbus_xfer_emulated(struct i2c_adapter *adapter, u16 addr,
 	bool wants_pec = ((flags & I2C_CLIENT_PEC) && size != I2C_SMBUS_QUICK
 			  && size != I2C_SMBUS_I2C_BLOCK_DATA);
 
-	/* Drivers must opt in to 255 byte max block size */
-	block_max = i2c_check_functionality(adapter, I2C_FUNC_SMBUS_V3_BLOCK)
-			? I2C_SMBUS_V3_BLOCK_MAX : I2C_SMBUS_BLOCK_MAX;
-
 	msgbuf0[0] = command;
 	switch (size) {
 	case I2C_SMBUS_QUICK:
@@ -405,7 +399,7 @@ static s32 i2c_smbus_xfer_emulated(struct i2c_adapter *adapter, u16 addr,
 			i2c_smbus_try_get_dmabuf(&msg[1], 0);
 		} else {
 			msg[0].len = data->block[0] + 2;
-			if (msg[0].len > block_max + 2) {
+			if (msg[0].len > I2C_SMBUS_BLOCK_MAX + 2) {
 				dev_err(&adapter->dev,
 					"Invalid block write size %d\n",
 					data->block[0]);
@@ -419,7 +413,7 @@ static s32 i2c_smbus_xfer_emulated(struct i2c_adapter *adapter, u16 addr,
 	case I2C_SMBUS_BLOCK_PROC_CALL:
 		nmsgs = 2; /* Another special case */
 		read_write = I2C_SMBUS_READ;
-		if (data->block[0] > block_max) {
+		if (data->block[0] > I2C_SMBUS_BLOCK_MAX) {
 			dev_err(&adapter->dev,
 				"Invalid block write size %d\n",
 				data->block[0]);
@@ -436,7 +430,7 @@ static s32 i2c_smbus_xfer_emulated(struct i2c_adapter *adapter, u16 addr,
 		i2c_smbus_try_get_dmabuf(&msg[1], 0);
 		break;
 	case I2C_SMBUS_I2C_BLOCK_DATA:
-		if (data->block[0] > block_max) {
+		if (data->block[0] > I2C_SMBUS_BLOCK_MAX) {
 			dev_err(&adapter->dev, "Invalid block %s size %d\n",
 				read_write == I2C_SMBUS_READ ? "read" : "write",
 				data->block[0]);
@@ -504,7 +498,7 @@ static s32 i2c_smbus_xfer_emulated(struct i2c_adapter *adapter, u16 addr,
 			break;
 		case I2C_SMBUS_BLOCK_DATA:
 		case I2C_SMBUS_BLOCK_PROC_CALL:
-			if (msg[1].buf[0] > block_max) {
+			if (msg[1].buf[0] > I2C_SMBUS_BLOCK_MAX) {
 				dev_err(&adapter->dev,
 					"Invalid block size returned: %d\n",
 					msg[1].buf[0]);