[PATCH v2 3/6] i2c: pasemi: Improve timeout handling

Sven Peter via B4 Relay
2025-04-15T15:37:17Z

From: Sven Peter <sven@svenpeter.dev>

Add proper timeout handling for the interrupt path.
Previously, this was only correctly done for the polling path.
Note that we drop reg_write(smbus, REG_SMSTA, status) here which
will be done anyway whenever the next transaction starts via
pasemi_smb_clear.

Signed-off-by: Sven Peter <sven@svenpeter.dev>
---
drivers/i2c/busses/i2c-pasemi-core.c | 24 +++++++++++++++++-------
1 file changed, 17 insertions(+), 7 deletions(-)

diff --git a/drivers/i2c/busses/i2c-pasemi-core.c b/drivers/i2c/busses/i2c-pasemi-core.c
index df1b0087dcacb0a3b94196368137d5e20b0e6d7e..9b611dbdfef23e78a4ea75ac0311938d52b6ba96 100644
--- a/drivers/i2c/busses/i2c-pasemi-core.c
+++ b/drivers/i2c/busses/i2c-pasemi-core.c
@@ -91,32 +91,42 @@ static void pasemi_smb_clear(struct pasemi_smbus *smbus)
static int pasemi_smb_waitready(struct pasemi_smbus *smbus)
{
int timeout = 100;
+ int ret;
unsigned int status;

if (smbus->use_irq) {
reinit_completion(&smbus->irq_completion);
reg_write(smbus, REG_IMASK, SMSTA_XEN | SMSTA_MTN);
- wait_for_completion_timeout(&smbus->irq_completion, msecs_to_jiffies(100));
+ ret = wait_for_completion_timeout(&smbus->irq_completion, msecs_to_jiffies(100));
reg_write(smbus, REG_IMASK, 0);
status = reg_read(smbus, REG_SMSTA);
+
+ if (ret < 0) {
+ dev_err(smbus->dev,
+ "Completion wait failed with %d, status 0x%08x\n",
+ ret, status);
+ return ret;
+ } else if (ret == 0) {
+ dev_warn(smbus->dev, "Timeout, status 0x%08x\n", status);
+ return -ETIME;
+ }
} else {
status = reg_read(smbus, REG_SMSTA);
while (!(status & SMSTA_XEN) && timeout--) {
msleep(1);
status = reg_read(smbus, REG_SMSTA);
}
+
+ if (timeout < 0) {
+ dev_warn(smbus->dev, "Timeout, status 0x%08x\n", status);
+ return -ETIME;
+ }
}

/* Got NACK? */
if (status & SMSTA_MTN)
return -ENXIO;

- if (timeout < 0) {
- dev_warn(smbus->dev, "Timeout, status 0x%08x\n", status);
- reg_write(smbus, REG_SMSTA, status);
- return -ETIME;
- }
-
/* Clear XEN */
reg_write(smbus, REG_SMSTA, SMSTA_XEN);

--
2.34.1