patrick/zephyr
1
0
Fork 0
Code Issues Pull requests Actions 8 Packages Projects Releases Wiki Activity

drivers: i3c: i3c_mcux: retry when timeout occurs in emit stop

Browse source 
Have seen timeout error occur when doing an emit stop at
end of a multiple register write to a mmc5633 mag sensor IC.
The i3c_mcux driver would return on such an error without
doing the k_condvar_broadcast(), since the stop wasn't
technically done (or unclear if it was), and then future
transfers requests waiting on the condvar could be blocked
forever. Add a limited retry when a timeout occurs to
avoid such a stall condition from happening.

Signed-off-by: Mike J. Chen <mjchen@google.com>
This commit is contained in:
Mike J. Chen 2024-03-12 18:33:31 -07:00 committed by Anas Nashif
parent a64d20f6f0
commit 5518b0c698
1 changed files with 77 additions and 16 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

93
drivers/i3c/i3c_mcux.c
View file

@ -63,6 +63,8 @@ LOG_MODULE_REGISTER(i3c_mcux, CONFIG_I3C_MCUX_LOG_LEVEL);
#define I3C_MSTATUS_IBITYPE_MR I3C_MSTATUS_IBITYPE(2)
#define I3C_MSTATUS_IBITYPE_HJ I3C_MSTATUS_IBITYPE(3)
#define I3C_MAX_STOP_RETRIES 5
struct mcux_i3c_config {
/** Common I3C Driver Config */
struct i3c_driver_config common;
@ -676,23 +678,18 @@ static int mcux_i3c_request_emit_start(I3C_Type *base, uint8_t addr, bool is_i2c
/**
* @brief Tell controller to emit STOP.
*
* This emits STOP when controller is in NORMACT state as this is
* the only valid state where STOP can be emitted. This also waits
* for the controller to get out of NORMACT before returning.
* This emits STOP and waits for controller to get out of NORMACT,
* checking for errors.
*
* @param base Pointer to controller registers.
* @param wait_stop True if need to wait for controller to be
* no longer in NORMACT.
*/
static inline void mcux_i3c_request_emit_stop(struct mcux_i3c_data *dev_data,
I3C_Type *base, bool wait_stop)
static inline int mcux_i3c_do_request_emit_stop(I3C_Type *base, bool wait_stop)
{
/* Make sure we are in a state where we can emit STOP */
if (mcux_i3c_state_get(base) == I3C_MSTATUS_STATE_NORMACT) {
reg32_update(&base->MCTRL,
I3C_MCTRL_REQUEST_MASK | I3C_MCTRL_DIR_MASK | I3C_MCTRL_RDTERM_MASK,
I3C_MCTRL_REQUEST_EMIT_STOP);
}
reg32_update(&base->MCTRL,
I3C_MCTRL_REQUEST_MASK | I3C_MCTRL_DIR_MASK | I3C_MCTRL_RDTERM_MASK,
I3C_MCTRL_REQUEST_EMIT_STOP);
/*
* EMIT_STOP request doesn't result in MCTRLDONE being cleared
@ -709,14 +706,78 @@ static inline void mcux_i3c_request_emit_stop(struct mcux_i3c_data *dev_data,
I3C_MSTATUS_STATE_NORMACT)) {
if (mcux_i3c_has_error(base)) {
/*
* Bail out if there is any error so
* we won't loop forever.
* A timeout error has been observed on
* an EMIT_STOP request. Refman doesn't say
* how that could occur but clear it
* and return the error.
*/
return;
if (reg32_test(&base->MERRWARN,
I3C_MERRWARN_TIMEOUT_MASK)) {
mcux_i3c_errwarn_clear_all_nowait(base);
return -ETIMEDOUT;
}
return -EIO;
}
k_busy_wait(10);
};
}
}
return 0;
}
/**
* @brief Tell controller to emit STOP.
*
* This emits STOP when controller is in NORMACT state as this is
* the only valid state where STOP can be emitted. This also waits
* for the controller to get out of NORMACT before returning and
* retries if any timeout errors occur during the emit STOP.
*
* @param dev_data Pointer to device driver data
* @param base Pointer to controller registers.
* @param wait_stop True if need to wait for controller to be
* no longer in NORMACT.
*/
static inline void mcux_i3c_request_emit_stop(struct mcux_i3c_data *dev_data,
I3C_Type *base, bool wait_stop)
{
size_t retries;
/*
* Stop is usually the last part of a transfer.
* Sometimes, an error occurred before. We want to clear
* it so any error as a result of emitting the stop
* itself doesn't get incorrectly mixed together.
*/
if (mcux_i3c_has_error(base)) {
mcux_i3c_errwarn_clear_all_nowait(base);
}
/* Make sure we are in a state where we can emit STOP */
if (!reg32_test_match(&base->MSTATUS, I3C_MSTATUS_STATE_MASK,
I3C_MSTATUS_STATE_NORMACT)) {
return;
}
retries = 0;
while (1) {
int err = mcux_i3c_do_request_emit_stop(base, wait_stop);
if (err) {
if ((err == -ETIMEDOUT) && (++retries <= I3C_MAX_STOP_RETRIES)) {
LOG_WRN("Timeout on emit stop, retrying");
continue;
}
LOG_ERR("Error waiting for stop");
return;
}
/*
* Success. If wait_stop was true, state should now
* be IDLE or possibly SLVREQ.
*/
if (retries) {
LOG_WRN("EMIT_STOP succeeded on %u retries", retries);
}
break;
}
/* Release any threads that might have been blocked waiting for IDLE */