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i2c-nforce2: Abort the transaction on error

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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: Oleg Ryjkov <olegr@olegr.ca>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
This commit is contained in:
Oleg Ryjkov 2007-10-13 23:56:33 +02:00 committed by Jean Delvare
parent 4153549734
commit d49584c4a3
1 changed files with 31 additions and 0 deletions
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31
drivers/i2c/busses/i2c-nforce2.c
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@ -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 */