diff options
| -rw-r--r-- | hw/p8-i2c.c | 58 |
1 files changed, 37 insertions, 21 deletions
diff --git a/hw/p8-i2c.c b/hw/p8-i2c.c index f4666e2..a627417 100644 --- a/hw/p8-i2c.c +++ b/hw/p8-i2c.c @@ -1063,8 +1063,11 @@ static int occ_i2c_lock(struct p8_i2c_master *master) busflag = PPC_BIT(16 + (master->engine_id - 1) * 2); - DBG("occflags = %llx (locks = %.6llx)\n", (u64)occflags, - GETFIELD(PPC_BITMASK(16, 22), occflags)); + DBG("I2C: c%de%d: occflags = %llx (locks = %x:%x:%x)\n", + master->chip_id, master->engine_id, (u64) occflags, + (u32) GETFIELD(PPC_BITMASK(16, 17), occflags), + (u32) GETFIELD(PPC_BITMASK(18, 19), occflags), + (u32) GETFIELD(PPC_BITMASK(20, 21), occflags)); rc = xscom_write(master->chip_id, OCCFLG_SET, busflag); if (rc) { @@ -1073,8 +1076,11 @@ static int occ_i2c_lock(struct p8_i2c_master *master) } /* If the OCC also has this bus locked then wait for IRQ */ - if (occflags & (busflag << 1)) + if (occflags & (busflag >> 1)) { + DBG("I2C: c%de%d: Master in use by OCC\n", + master->chip_id, master->engine_id); return 1; + } master->occ_lock_acquired = true; @@ -1098,8 +1104,8 @@ static int occ_i2c_unlock(struct p8_i2c_master *master) busflag = PPC_BIT(16 + (master->engine_id - 1) * 2); if (!(occflags & busflag)) { - prerror("I2C: busflag for %d already cleared (flags = %.16llx)", - master->engine_id, occflags); + DBG("I2C: spurious unlock for c%de%d already cleared (flags = %.16llx)", + master->chip_id, master->engine_id, occflags); } rc = xscom_write(master->chip_id, OCCFLG_CLEAR, busflag); @@ -1161,7 +1167,7 @@ static int p8_i2c_start_request(struct p8_i2c_master *master, if (rc > 0) { /* Wait for OCC IRQ */ master->state = state_occache_dis; - schedule_timer(&master->recovery, rc); + schedule_timer(&master->recovery, msecs_to_tb(10)); return 0; } @@ -1281,29 +1287,29 @@ void p9_i2c_bus_owner_change(u32 chip_id) { struct proc_chip *chip = get_chip(chip_id); struct p8_i2c_master *master = NULL; - int rc; assert(chip); list_for_each(&chip->i2cms, master, link) { - if (master->state == state_idle || - master->state != state_occache_dis) - continue; - lock(&master->lock); + /* spurious */ + if (master->state != state_occache_dis) + goto done; + /* Can we now lock this master? */ - rc = occ_i2c_lock(master); - if (rc) { - unlock(&master->lock); - continue; - } + if (occ_i2c_lock(master)) + goto done; - /* Run the state machine */ - p8_i2c_check_status(master); + /* clear the existing wait timer */ + cancel_timer(&master->recovery); + + /* re-start the request now that we own the master */ + master->state = state_idle; - /* Check for new work */ p8_i2c_check_work(master); + p8_i2c_check_status(master); +done: unlock(&master->lock); } } @@ -1453,8 +1459,18 @@ static void p8_i2c_recover(struct timer *t __unused, void *data, struct p8_i2c_master *master = data; lock(&master->lock); - assert(master->state == state_recovery || - master->state == state_occache_dis); + + /* + * The recovery timer can race with the OCC interrupt. If the interrupt + * comes in just before this is called, then we'll get a spurious + * timeout which we need to ignore. + */ + if (master->state != state_recovery && + master->state != state_occache_dis) { + unlock(&master->lock); + return; + } + master->state = state_idle; /* We may or may not still have work pending, re-enable the sensor cache |