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| author | Heiner Kallweit <hkallweit1@gmail.com> | 2024-02-02 08:04:06 +0100 |
|---|---|---|
| committer | Andi Shyti <andi.shyti@kernel.org> | 2024-02-08 18:06:46 +0100 |
| commit | 29dae4572efb676e4831eee68bc423b9f32c05d0 (patch) | |
| tree | 2e7bd3b494a758a662a12772bf995ddabe73368f /drivers/i2c/busses | |
| parent | 6ff9d46cd36fbd004b1cd7c9173af5cdfbcd1df1 (diff) | |
| download | linux-29dae4572efb676e4831eee68bc423b9f32c05d0.tar.gz | |
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 <hkallweit1@gmail.com>
Reviewed-by: Andi Shyti <andi.shyti@kernel.org>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
Diffstat (limited to 'drivers/i2c/busses')
| -rw-r--r-- | drivers/i2c/busses/i2c-i801.c | 22 |
1 files changed, 16 insertions, 6 deletions
diff --git a/drivers/i2c/busses/i2c-i801.c b/drivers/i2c/busses/i2c-i801.c index 24eb187dbc1f54..15d2512883171a 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 <linux/pci_ids.h> */ #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; |