From 29dae4572efb676e4831eee68bc423b9f32c05d0 Mon Sep 17 00:00:00 2001 From: Heiner Kallweit Date: Fri, 2 Feb 2024 08:04:06 +0100 Subject: i2c: i801: Add SMBUS_LEN_SENTINEL Add a sentinel length value that is used to check whether we should read and use the length value provided by the slave device. This simplifies the currently used checks. Signed-off-by: Heiner Kallweit Reviewed-by: Andi Shyti Signed-off-by: Andi Shyti --- drivers/i2c/busses/i2c-i801.c | 22 ++++++++++++++++------ 1 file changed, 16 insertions(+), 6 deletions(-) diff --git a/drivers/i2c/busses/i2c-i801.c b/drivers/i2c/busses/i2c-i801.c index 24eb187dbc1f..15d251288317 100644 --- a/drivers/i2c/busses/i2c-i801.c +++ b/drivers/i2c/busses/i2c-i801.c @@ -205,6 +205,8 @@ #define STATUS_FLAGS (SMBHSTSTS_BYTE_DONE | SMBHSTSTS_INTR | \ STATUS_ERROR_FLAGS) +#define SMBUS_LEN_SENTINEL (I2C_SMBUS_BLOCK_MAX + 1) + /* Older devices have their ID defined in */ #define PCI_DEVICE_ID_INTEL_COMETLAKE_SMBUS 0x02a3 #define PCI_DEVICE_ID_INTEL_COMETLAKE_H_SMBUS 0x06a3 @@ -541,9 +543,12 @@ out: static void i801_isr_byte_done(struct i801_priv *priv) { if (priv->is_read) { - /* For SMBus block reads, length is received with first byte */ - if (((priv->cmd & 0x1c) == I801_BLOCK_DATA) && - (priv->count == 0)) { + /* + * At transfer start i801_smbus_block_transaction() marks + * the block length as invalid. Check for this sentinel value + * and read the block length from SMBHSTDAT0. + */ + if (priv->len == SMBUS_LEN_SENTINEL) { priv->len = inb_p(SMBHSTDAT0(priv)); if (priv->len < 1 || priv->len > I2C_SMBUS_BLOCK_MAX) { dev_err(&priv->pci_dev->dev, @@ -698,8 +703,12 @@ static int i801_block_transaction_byte_by_byte(struct i801_priv *priv, if (status) return status; - if (i == 1 && read_write == I2C_SMBUS_READ - && command != I2C_SMBUS_I2C_BLOCK_DATA) { + /* + * At transfer start i801_smbus_block_transaction() marks + * the block length as invalid. Check for this sentinel value + * and read the block length from SMBHSTDAT0. + */ + if (len == SMBUS_LEN_SENTINEL) { len = inb_p(SMBHSTDAT0(priv)); if (len < 1 || len > I2C_SMBUS_BLOCK_MAX) { dev_err(&priv->pci_dev->dev, @@ -806,7 +815,8 @@ static int i801_smbus_block_transaction(struct i801_priv *priv, union i2c_smbus_ u8 addr, u8 hstcmd, char read_write, int command) { if (read_write == I2C_SMBUS_READ && command == I2C_SMBUS_BLOCK_DATA) - data->block[0] = I2C_SMBUS_BLOCK_MAX; + /* Mark block length as invalid */ + data->block[0] = SMBUS_LEN_SENTINEL; else if (data->block[0] < 1 || data->block[0] > I2C_SMBUS_BLOCK_MAX) return -EPROTO; -- cgit v1.2.3