Commit d49584c4 authored by Oleg Ryjkov's avatar Oleg Ryjkov Committed by Jean Delvare
Browse files

i2c-nforce2: Abort the transaction on error 



This patch is to add an abort function that will bring back the MCP51/55
controller if it was blocked by a block-read operation, in particular.
(When a slave sends a wrong byte count on a byte read, the host gets
locked up). I've only tested it on an MCP51 and MCP55. However, I'm
almost certain it will also work on MCP65, I just did not have the board
to test it on. Thus for now the abort function will only be called
if an MCP51/55 was detected.

Signed-off-by: default avatarOleg Ryjkov <olegr@olegr.ca>
Signed-off-by: default avatarJean Delvare <khali@linux-fr.org>
parent 41535497

drivers/i2c/busses/i2c-nforce2.c

+32 −1
Original line number Diff line number Diff line
@@ -62,6 +62,7 @@ struct nforce2_smbus { 
	int base;

	int size;

	int blockops;

	int can_abort;

};
@@ -83,7 +84,14 @@ struct nforce2_smbus { 
#define NVIDIA_SMB_DATA		(smbus->base + 0x04)	/* 32 data registers */

#define NVIDIA_SMB_BCNT		(smbus->base + 0x24)	/* number of data

							   bytes */



#define NVIDIA_SMB_STATUS_ABRT	(smbus->base + 0x3c)	/* register used to

							   check the status of

							   the abort command */

#define NVIDIA_SMB_CTRL		(smbus->base + 0x3e)	/* control register */



#define NVIDIA_SMB_STATUS_ABRT_STS	0x01		/* Bit to notify that

							   abort succeeded */

#define NVIDIA_SMB_CTRL_ABORT	0x20

#define NVIDIA_SMB_STS_DONE	0x80

#define NVIDIA_SMB_STS_ALRM	0x40

#define NVIDIA_SMB_STS_RES	0x20
@@ -103,6 +111,25 @@ struct nforce2_smbus { 


static struct pci_driver nforce2_driver;



static void nforce2_abort(struct i2c_adapter *adap)

{

	struct nforce2_smbus *smbus = adap->algo_data;

	int timeout = 0;

	unsigned char temp;



	dev_dbg(&adap->dev, "Aborting current transaction\n");



	outb_p(NVIDIA_SMB_CTRL_ABORT, NVIDIA_SMB_CTRL);

	do {

		msleep(1);

		temp = inb_p(NVIDIA_SMB_STATUS_ABRT);

	} while (!(temp & NVIDIA_SMB_STATUS_ABRT_STS) &&

			(timeout++ < MAX_TIMEOUT));

	if (!(temp & NVIDIA_SMB_STATUS_ABRT_STS))

		dev_err(&adap->dev, "Can't reset the smbus\n");

	outb_p(NVIDIA_SMB_STATUS_ABRT_STS, NVIDIA_SMB_STATUS_ABRT);

}



static int nforce2_check_status(struct i2c_adapter *adap)

{

	struct nforce2_smbus *smbus = adap->algo_data;
@@ -116,6 +143,8 @@ static int nforce2_check_status(struct i2c_adapter *adap) 


	if (timeout >= MAX_TIMEOUT) {

		dev_dbg(&adap->dev, "SMBus Timeout!\n");

		if (smbus->can_abort)

			nforce2_abort(adap);

		return -1;

	}

	if (!(temp & NVIDIA_SMB_STS_DONE) || (temp & NVIDIA_SMB_STS_STATUS)) {
@@ -325,6 +354,8 @@ static int __devinit nforce2_probe(struct pci_dev *dev, const struct pci_device_ 
	case PCI_DEVICE_ID_NVIDIA_NFORCE_MCP55_SMBUS:

		smbuses[0].blockops = 1;

		smbuses[1].blockops = 1;

		smbuses[0].can_abort = 1;

		smbuses[1].can_abort = 1;

	}



	/* SMBus adapter 1 */

CRA Git | Maintained and supported by SUSTech CRA and CCSE