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F-10836 - Scrub timed-out I2C staging

pull/582/head
Aidan Garske 2026-08-22 14:06:00 -07:00
parent 31fdfbfb83
commit 69417182ea
1 changed files with 34 additions and 8 deletions
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42
hal/tpm_io_microchip.c
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@ -76,8 +76,8 @@
static byte i2cXferBuf[MAX_SPI_FRAMESIZE+1];
static byte i2cRdBuf[MAX_SPI_FRAMESIZE];
/* Set when a busy timeout leaves plaintext in a staging buffer that could
* not be scrubbed; cleared by the next call that finds the engine idle. */
static int i2cXferDirty = 0;
* not be scrubbed; cleared on completion or once polling finds idle. */
static volatile int i2cXferDirty = 0;
/* Scrub staging left dirty by a previous busy timeout. Only safe once the
* engine is idle, so callers must check I2C_BB_IsBusy() first. */
@ -90,10 +90,12 @@
}
}
static void dummy_callback(uintptr_t context)
static void i2c_completion_callback(uintptr_t context)
{
(void) context;
return;
/* Successful transfers leave this clear. A timed-out transfer sets
* it while the engine still owns the staging buffers. */
i2c_scrub_stale();
}
/* Wait for time_ms using Microchip Harmony SYS_TIME API. */
@ -116,6 +118,18 @@
return;
}
static void i2c_timeout_cleanup(void)
{
int busy_retry = TPM_I2C_TRIES;
while (i2cXferDirty && I2C_BB_IsBusy() && --busy_retry > 0) {
microchip_wait(250);
}
if (!I2C_BB_IsBusy()) {
i2c_scrub_stale();
}
}
/* Microchip Harmony I2C */
static int i2c_read(void* userCtx, word32 reg, byte* data, int len)
{
@ -198,8 +212,11 @@
if (I2C_BB_IsBusy()) {
/* Engine still owns i2cRdBuf; it cannot be scrubbed here, so
* flag it for the next call that finds the engine idle */
* defer scrubbing until the completion callback. */
i2cXferDirty = 1;
if (!I2C_BB_IsBusy()) {
i2c_scrub_stale();
}
printf("error: i2c_read: busy wait timed out\n");
return -1;
}
@ -269,9 +286,11 @@
if (I2C_BB_IsBusy()) {
/* Engine is still clocking out i2cXferBuf, so it cannot be
* scrubbed here; flag it for the next call that finds the
* engine idle */
* scrubbed here; defer until the completion callback. */
i2cXferDirty = 1;
if (!I2C_BB_IsBusy()) {
i2c_scrub_stale();
}
printf("error: i2c_write: busy wait timed out\n");
return -1;
}
@ -305,7 +324,7 @@
* even if not used.
* */
I2C_BB_Initialize();
I2C_BB_CallbackRegister(dummy_callback, dummy_context);
I2C_BB_CallbackRegister(i2c_completion_callback, dummy_context);
if (isRead) {
ret = i2c_read(userCtx, addr, buf, size);
@ -314,6 +333,13 @@
ret = i2c_write(userCtx, addr, buf, size);
}
/* A timed-out transfer may complete after i2c_read/write returns.
* Poll once more here; the registered callback handles completion
* after this bounded cleanup wait. */
if (i2cXferDirty) {
i2c_timeout_cleanup();
}
(void)userCtx;
(void)ctx;