Commit 70f3d366 authored by Atharva Tiwari's avatar Atharva Tiwari Committed by Andi Shyti
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i2c: amd756: Fix endianness handling for word data 



Ensure correct handling of "endianness"
for word-sized data in amd756_access

 - Convert word data into little-endian using cpu_to_le16
 - Convert word data from little-endian
   to cpu native format using le16_to_cpu

This fixes poteential issues on big-endian systems and
ensure proper byte ordering for SMBus word transacitions

Signed-off-by: default avatarAtharva Tiwari <evepolonium@gmail.com>
Link: https://lore.kernel.org/r/20250101103422.30523-1-evepolonium@gmail.com


Signed-off-by: default avatarAndi Shyti <andi.shyti@kernel.org>
parent 1ee867e4

drivers/i2c/busses/i2c-amd756.c

+3 −2
Original line number Diff line number Diff line
@@ -31,6 +31,7 @@ 
#include <linux/i2c.h>

#include <linux/acpi.h>

#include <linux/io.h>

#include <linux/byteorder/generic.h>



/* AMD756 SMBus address offsets */

#define SMB_ADDR_OFFSET		0xE0
@@ -211,7 +212,7 @@ static s32 amd756_access(struct i2c_adapter * adap, u16 addr, 
		       SMB_HOST_ADDRESS);

		outb_p(command, SMB_HOST_COMMAND);

		if (read_write == I2C_SMBUS_WRITE)

			outw_p(data->word, SMB_HOST_DATA);	/* TODO: endian???? */

			outw_p(cpu_to_le16((u16)data->word), SMB_HOST_DATA);

		size = AMD756_WORD_DATA;

		break;

	case I2C_SMBUS_BLOCK_DATA:
@@ -256,7 +257,7 @@ static s32 amd756_access(struct i2c_adapter * adap, u16 addr, 
		data->byte = inw_p(SMB_HOST_DATA);

		break;

	case AMD756_WORD_DATA:

		data->word = inw_p(SMB_HOST_DATA);	/* TODO: endian???? */

		data->word = (u16)le16_to_cpu(inw_p(SMB_HOST_DATA));

		break;

	case AMD756_BLOCK_DATA:

		data->block[0] = inw_p(SMB_HOST_DATA) & 0x3f;