Commit f4f64fa8 authored by Hector Martin's avatar Hector Martin Committed by Andi Shyti
Browse files

i2c: pasemi: Improve error recovery 



Add handling for all the missing error condition, and better recovery in
pasemi_smb_clear().

Reviewed-by: default avatarAlyssa Rosenzweig <alyssa@rosenzweig.io>
Reviewed-by: default avatarNeal Gompa <neal@gompa.dev>
Signed-off-by: default avatarHector Martin <marcan@marcan.st>
Co-developed-by: default avatarSven Peter <sven@svenpeter.dev>
Signed-off-by: default avatarSven Peter <sven@svenpeter.dev>
Link: https://lore.kernel.org/r/20250427-pasemi-fixes-v3-3-af28568296c0@svenpeter.dev


Signed-off-by: default avatarAndi Shyti <andi.shyti@kernel.org>
parent 390b8f58

drivers/i2c/busses/i2c-pasemi-core.c

+54 −7
Original line number Diff line number Diff line
@@ -87,12 +87,31 @@ static void pasemi_reset(struct pasemi_smbus *smbus) 
	reinit_completion(&smbus->irq_completion);

}



static void pasemi_smb_clear(struct pasemi_smbus *smbus)

static int pasemi_smb_clear(struct pasemi_smbus *smbus)

{

	unsigned int status;

	int ret;



	status = reg_read(smbus, REG_SMSTA);

	/* First wait for the bus to go idle */

	ret = readx_poll_timeout(ioread32, smbus->ioaddr + REG_SMSTA,

				 status, !(status & (SMSTA_XIP | SMSTA_JAM)),

				 USEC_PER_MSEC,

				 USEC_PER_MSEC * PASEMI_TRANSFER_TIMEOUT_MS);



	if (ret < 0) {

		dev_err(smbus->dev, "Bus is still stuck (status 0x%08x)\n", status);

		return -EIO;

	}



	/* If any badness happened or there is data in the FIFOs, reset the FIFOs */

	if ((status & (SMSTA_MRNE | SMSTA_JMD | SMSTA_MTO | SMSTA_TOM | SMSTA_MTN | SMSTA_MTA)) ||

	    !(status & SMSTA_MTE))

		pasemi_reset(smbus);



	/* Clear the flags */

	reg_write(smbus, REG_SMSTA, status);



	return 0;

}



static int pasemi_smb_waitready(struct pasemi_smbus *smbus)
@@ -130,9 +149,35 @@ static int pasemi_smb_waitready(struct pasemi_smbus *smbus) 
		}

	}



	/* Controller timeout? */

	if (status & SMSTA_TOM) {

		dev_err(smbus->dev, "Controller timeout, status 0x%08x\n", status);

		return -EIO;

	}



	/* Peripheral timeout? */

	if (status & SMSTA_MTO) {

		dev_err(smbus->dev, "Peripheral timeout, status 0x%08x\n", status);

		return -ETIME;

	}



	/* Still stuck in a transaction? */

	if (status & SMSTA_XIP) {

		dev_err(smbus->dev, "Bus stuck, status 0x%08x\n", status);

		return -EIO;

	}



	/* Arbitration loss? */

	if (status & SMSTA_MTA) {

		dev_err(smbus->dev, "Arbitration loss, status 0x%08x\n", status);

		return -EBUSY;

	}



	/* Got NACK? */

	if (status & SMSTA_MTN)

	if (status & SMSTA_MTN) {

		dev_err(smbus->dev, "NACK, status 0x%08x\n", status);

		return -ENXIO;

	}



	/* Clear XEN */

	reg_write(smbus, REG_SMSTA, SMSTA_XEN);
@@ -194,9 +239,9 @@ static int pasemi_i2c_xfer(struct i2c_adapter *adapter, 
	struct pasemi_smbus *smbus = adapter->algo_data;

	int ret, i;



	pasemi_smb_clear(smbus);



	ret = 0;

	ret = pasemi_smb_clear(smbus);

	if (ret)

		return ret;



	for (i = 0; i < num && !ret; i++)

		ret = pasemi_i2c_xfer_msg(adapter, &msgs[i], (i == (num - 1)));
@@ -217,7 +262,9 @@ static int pasemi_smb_xfer(struct i2c_adapter *adapter, 
	addr <<= 1;

	read_flag = read_write == I2C_SMBUS_READ;



	pasemi_smb_clear(smbus);

	err = pasemi_smb_clear(smbus);

	if (err)

		return err;



	switch (size) {

	case I2C_SMBUS_QUICK: