svn commit: r187473 - head/sys/powerpc/powermac
Nathan Whitehorn
nwhitehorn at FreeBSD.org
Tue Jan 20 06:09:13 PST 2009
Author: nwhitehorn
Date: Tue Jan 20 14:09:12 2009
New Revision: 187473
URL: http://svn.freebsd.org/changeset/base/187473
Log:
Fix a race condition in kiic(4) made possible by the way the device's STOP
condition is sent. We used to put the bus in the STOP state, but returned
without waiting for that to actually occur.
Submitted by: Marco Trillo
Modified:
head/sys/powerpc/powermac/kiic.c
Modified: head/sys/powerpc/powermac/kiic.c
==============================================================================
--- head/sys/powerpc/powermac/kiic.c Tue Jan 20 14:06:30 2009 (r187472)
+++ head/sys/powerpc/powermac/kiic.c Tue Jan 20 14:09:12 2009 (r187473)
@@ -230,7 +230,7 @@ static void
kiic_writereg(struct kiic_softc *sc, u_int reg, u_int val)
{
bus_write_1(sc->sc_reg, sc->sc_regstep * reg, val);
- DELAY(10); /* XXX why? */
+ DELAY(10); /* register access delay */
}
static u_int
@@ -289,18 +289,22 @@ kiic_intr(void *xsc)
}
if (isr & I2C_INT_DATA) {
- if (sc->sc_resid > 0) {
- if (sc->sc_flags & I2C_READING) {
+ if (sc->sc_flags & I2C_READING) {
+ if (sc->sc_resid > 0) {
*sc->sc_data++ = kiic_readreg(sc, DATA);
sc->sc_resid--;
+ }
+
+ } else {
+ if (sc->sc_resid == 0) {
+ x = kiic_readreg(sc, CONTROL);
+ x |= I2C_CT_STOP;
+ kiic_writereg(sc, CONTROL, x);
} else {
kiic_writereg(sc, DATA, *sc->sc_data++);
sc->sc_resid--;
}
}
-
- if (sc->sc_resid == 0)
- wakeup(sc->sc_dev);
}
if (isr & I2C_INT_STOP) {
@@ -317,7 +321,7 @@ static int
kiic_transfer(device_t dev, struct iic_msg *msgs, uint32_t nmsgs)
{
struct kiic_softc *sc;
- int i, x, timo;
+ int i, x, timo, err;
uint8_t addr;
sc = device_get_softc(dev);
@@ -341,6 +345,7 @@ kiic_transfer(device_t dev, struct iic_m
sc->sc_flags = I2C_BUSY;
addr = msgs[i].slave;
timo = 1000 + sc->sc_resid * 200;
+ timo += 100000;
if (msgs[i].flags & IIC_M_RD) {
sc->sc_flags |= I2C_READING;
@@ -353,19 +358,13 @@ kiic_transfer(device_t dev, struct iic_m
x = kiic_readreg(sc, CONTROL) | I2C_CT_ADDR;
kiic_writereg(sc, CONTROL, x);
- mtx_sleep(dev, &sc->sc_mutex, 0, "kiic", timo);
-
- if (!(sc->sc_flags & I2C_READING)) {
- x = kiic_readreg(sc, CONTROL) | I2C_CT_STOP;
- kiic_writereg(sc, CONTROL, x);
- }
-
- mtx_sleep(dev, &sc->sc_mutex, 0, "kiic", timo);
-
+ err = mtx_sleep(dev, &sc->sc_mutex, 0, "kiic", timo);
+
msgs[i].len -= sc->sc_resid;
- if (sc->sc_flags & I2C_ERROR) {
- device_printf(sc->sc_dev, "I2C_ERROR\n");
+ if ((sc->sc_flags & I2C_ERROR) || err == EWOULDBLOCK) {
+ device_printf(sc->sc_dev, "I2C error\n");
+ sc->sc_flags = 0;
mtx_unlock(&sc->sc_mutex);
return (-1);
}
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