Author: wulf
Date: Sun Nov 3 21:07:12 2019
New Revision: 354314
URL: https://svnweb.freebsd.org/changeset/base/354314
Log:
[ig4] Improve error detection
Handle error bits of INTR_STAT and TX_ABORT registers.
Move interrupt clearing from interrupt handler to polling loop to get
common execution path with polled mode.
Do not clear interrupts with reading of IG4_REG_CLR_INTR register as
interrupts, triggered during the period from reg_read(IG4_REG_INTR_STAT)
to reg_read(IG4_REG_CLR_INTR) will be missed.
Instead, read each IG4_REG_CLR_* register separately.
Modified:
head/sys/dev/ichiic/ig4_iic.c
head/sys/dev/ichiic/ig4_reg.h
Modified: head/sys/dev/ichiic/ig4_iic.c
==============================================================================
--- head/sys/dev/ichiic/ig4_iic.c Sun Nov 3 21:06:06 2019
(r354313)
+++ head/sys/dev/ichiic/ig4_iic.c Sun Nov 3 21:07:12 2019
(r354314)
@@ -164,6 +164,55 @@ set_intr_mask(ig4iic_softc_t *sc, uint32_t val)
}
}
+static int
+intrstat2iic(ig4iic_softc_t *sc, uint32_t val)
+{
+ uint32_t src;
+
+ if (val & IG4_INTR_RX_UNDER)
+ reg_read(sc, IG4_REG_CLR_RX_UNDER);
+ if (val & IG4_INTR_RX_OVER)
+ reg_read(sc, IG4_REG_CLR_RX_OVER);
+ if (val & IG4_INTR_TX_OVER)
+ reg_read(sc, IG4_REG_CLR_TX_OVER);
+
+ if (val & IG4_INTR_TX_ABRT) {
+ src = reg_read(sc, IG4_REG_TX_ABRT_SOURCE);
+ reg_read(sc, IG4_REG_CLR_TX_ABORT);
+ /* User-requested abort. Not really a error */
+ if (src & IG4_ABRTSRC_TRANSFER)
+ return (IIC_ESTATUS);
+ /* Master has lost arbitration */
+ if (src & IG4_ABRTSRC_ARBLOST)
+ return (IIC_EBUSBSY);
+ /* Did not receive an acknowledge from the remote slave */
+ if (src & (IG4_ABRTSRC_TXNOACK_ADDR7 |
+ IG4_ABRTSRC_TXNOACK_ADDR10_1 |
+ IG4_ABRTSRC_TXNOACK_ADDR10_2 |
+ IG4_ABRTSRC_TXNOACK_DATA |
+ IG4_ABRTSRC_GENCALL_NOACK))
+ return (IIC_ENOACK);
+ /* Programming errors */
+ if (src & (IG4_ABRTSRC_GENCALL_READ |
+ IG4_ABRTSRC_NORESTART_START |
+ IG4_ABRTSRC_NORESTART_10))
+ return (IIC_ENOTSUPP);
+ /* Other errors */
+ if (src & IG4_ABRTSRC_ACKED_START)
+ return (IIC_EBUSERR);
+ }
+ /*
+ * TX_OVER, RX_OVER and RX_UNDER are caused by wrong RX/TX FIFO depth
+ * detection or driver's read/write pipelining errors.
+ */
+ if (val & (IG4_INTR_TX_OVER | IG4_INTR_RX_OVER))
+ return (IIC_EOVERFLOW);
+ if (val & IG4_INTR_RX_UNDER)
+ return (IIC_EUNDERFLOW);
+
+ return (IIC_NOERR);
+}
+
/*
* Enable or disable the controller and wait for the controller to acknowledge
* the state change.
@@ -209,17 +258,14 @@ wait_intr(ig4iic_softc_t *sc, uint32_t intr)
u_int count_us = 0;
u_int limit_us = 25000; /* 25ms */
- error = IIC_ETIMEOUT;
-
for (;;) {
/*
* Check requested status
*/
v = reg_read(sc, IG4_REG_RAW_INTR_STAT);
- if (v & intr) {
- error = 0;
+ error = intrstat2iic(sc, v & IG4_INTR_ERR_MASK);
+ if (error || (v & intr))
break;
- }
/*
* When waiting for the transmit FIFO to become empty,
@@ -237,15 +283,17 @@ wait_intr(ig4iic_softc_t *sc, uint32_t intr)
/*
* Stop if we've run out of time.
*/
- if (count_us >= limit_us)
+ if (count_us >= limit_us) {
+ error = IIC_ETIMEOUT;
break;
+ }
/*
* When polling is not requested let the interrupt do its work.
*/
if (!DO_POLL(sc)) {
mtx_lock(&sc->io_lock);
- set_intr_mask(sc, intr);
+ set_intr_mask(sc, intr | IG4_INTR_ERR_MASK);
mtx_sleep(sc, &sc->io_lock, 0, "i2cwait",
(hz + 99) / 100); /* sleep up to 10ms */
set_intr_mask(sc, 0);
@@ -307,9 +355,17 @@ set_slave_addr(ig4iic_softc_t *sc, uint8_t slave)
* IICBUS API FUNCTIONS
*/
static int
-ig4iic_xfer_start(ig4iic_softc_t *sc, uint16_t slave)
+ig4iic_xfer_start(ig4iic_softc_t *sc, uint16_t slave, bool repeated_start)
{
set_slave_addr(sc, slave >> 1);
+
+ if (!repeated_start) {
+ /*
+ * Clear any previous TX/RX FIFOs overflow/underflow bits.
+ */
+ reg_read(sc, IG4_REG_CLR_INTR);
+ }
+
return (0);
}
@@ -374,7 +430,6 @@ ig4iic_read(ig4iic_softc_t *sc, uint8_t *buf, uint16_t
}
}
out:
- (void)reg_read(sc, IG4_REG_TX_ABRT_SOURCE);
return (error);
}
@@ -410,7 +465,6 @@ ig4iic_write(ig4iic_softc_t *sc, uint8_t *buf, uint16_
}
}
- (void)reg_read(sc, IG4_REG_TX_ABRT_SOURCE);
return (error);
}
@@ -509,7 +563,7 @@ ig4iic_transfer(device_t dev, struct iic_msg *msgs, ui
error = 0;
for (i = 0; i < nmsgs; i++) {
if ((msgs[i].flags & IIC_M_NOSTART) == 0) {
- error = ig4iic_xfer_start(sc, msgs[i].slave);
+ error = ig4iic_xfer_start(sc, msgs[i].slave, rpstart);
} else {
if (!sc->slave_valid ||
(msgs[i].slave >> 1) != sc->last_slave) {
@@ -1019,8 +1073,8 @@ ig4iic_intr(void *cookie)
mtx_lock(&sc->io_lock);
/* Ignore stray interrupts */
if (sc->intr_mask != 0 && reg_read(sc, IG4_REG_INTR_STAT) != 0) {
+ /* Interrupt bits are cleared in wait_intr() loop */
set_intr_mask(sc, 0);
- reg_read(sc, IG4_REG_CLR_INTR);
wakeup(sc);
}
mtx_unlock(&sc->io_lock);
Modified: head/sys/dev/ichiic/ig4_reg.h
==============================================================================
--- head/sys/dev/ichiic/ig4_reg.h Sun Nov 3 21:06:06 2019
(r354313)
+++ head/sys/dev/ichiic/ig4_reg.h Sun Nov 3 21:07:12 2019
(r354314)
@@ -328,6 +328,9 @@
#define IG4_INTR_RX_OVER 0x0002
#define IG4_INTR_RX_UNDER 0x0001
+#define IG4_INTR_ERR_MASK (IG4_INTR_TX_ABRT | IG4_INTR_TX_OVER | \
+ IG4_INTR_RX_OVER | IG4_INTR_RX_UNDER)
+
/*
* RX_TL - (RW) Receive FIFO Threshold Register 22.2.11
* TX_TL - (RW) Transmit FIFO Threshold Register 22.2.12
@@ -435,8 +438,8 @@
#define IG4_ABRTSRC_NORESTART_10 0x00000400 /* RESTART disabled */
#define IG4_ABRTSRC_NORESTART_START 0x00000200 /* RESTART disabled */
#define IG4_ABRTSRC_ACKED_START 0x00000080 /* Improper acked
START */
-#define IG4_ABRTSRC_GENCALL_NOACK 0x00000020 /* Improper GENCALL */
-#define IG4_ABRTSRC_GENCALL_READ 0x00000010 /* Nobody acked GENCALL */
+#define IG4_ABRTSRC_GENCALL_READ 0x00000020 /* Improper GENCALL */
+#define IG4_ABRTSRC_GENCALL_NOACK 0x00000010 /* Nobody acked GENCALL */
#define IG4_ABRTSRC_TXNOACK_DATA 0x00000008 /* data phase no ACK */
#define IG4_ABRTSRC_TXNOACK_ADDR10_2 0x00000004 /* addr10/1 phase no ACK */
#define IG4_ABRTSRC_TXNOACK_ADDR10_1 0x00000002 /* addr10/2 phase no ACK */
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