The patch titled
I2C-MPC: Fix up error handling
has been added to the -mm tree. Its filename is
i2c-mpc-fix-up-error-handling.patch
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
From: Kumar Gala <galak@xxxxxxxxxxxxxxxxxxx>
* If we have an Unfinished (MCF) or Arbitration Lost (MAL) error and
the bus is still busy reset the controller. This prevents the
controller from getting in a hung state for transactions for other
devices.
* Fixed up propogating the errors from i2c_wait.
Signed-off-by: Kumar Gala <galak@xxxxxxxxxxxxxxxxxxx>
Cc: Jean Delvare <khali@xxxxxxxxxxxx>
Cc: Greg KH <greg@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
drivers/i2c/busses/i2c-mpc.c | 43 +++++++++++++++++++++++----------
1 files changed, 31 insertions(+), 12 deletions(-)
diff -puN drivers/i2c/busses/i2c-mpc.c~i2c-mpc-fix-up-error-handling drivers/i2c/busses/i2c-mpc.c
--- devel/drivers/i2c/busses/i2c-mpc.c~i2c-mpc-fix-up-error-handling 2006-04-18 23:09:01.000000000 -0700
+++ devel-akpm/drivers/i2c/busses/i2c-mpc.c 2006-04-18 23:09:01.000000000 -0700
@@ -115,11 +115,20 @@ static int i2c_wait(struct mpc_i2c *i2c,
if (!(x & CSR_MCF)) {
pr_debug("I2C: unfinished\n");
+
+ /* reset the controller if the bus is still busy */
+ if (x & CSR_MBB)
+ writeccr(i2c, 0);
+
return -EIO;
}
if (x & CSR_MAL) {
pr_debug("I2C: MAL\n");
+
+ /* reset the controller if the bus is still busy */
+ if (x & CSR_MBB)
+ writeccr(i2c, 0);
return -EIO;
}
@@ -160,7 +169,7 @@ static void mpc_i2c_stop(struct mpc_i2c
static int mpc_write(struct mpc_i2c *i2c, int target,
const u8 * data, int length, int restart)
{
- int i;
+ int i, ret;
unsigned timeout = i2c->adap.timeout;
u32 flags = restart ? CCR_RSTA : 0;
@@ -172,15 +181,17 @@ static int mpc_write(struct mpc_i2c *i2c
/* Write target byte */
writeb((target << 1), i2c->base + MPC_I2C_DR);
- if (i2c_wait(i2c, timeout, 1) < 0)
- return -1;
+ ret = i2c_wait(i2c, timeout, 1);
+ if (ret < 0)
+ return ret;
for (i = 0; i < length; i++) {
/* Write data byte */
writeb(data[i], i2c->base + MPC_I2C_DR);
- if (i2c_wait(i2c, timeout, 1) < 0)
- return -1;
+ ret = i2c_wait(i2c, timeout, 1);
+ if (ret < 0)
+ return ret;
}
return 0;
@@ -190,7 +201,7 @@ static int mpc_read(struct mpc_i2c *i2c,
u8 * data, int length, int restart)
{
unsigned timeout = i2c->adap.timeout;
- int i;
+ int i, ret;
u32 flags = restart ? CCR_RSTA : 0;
/* Start with MEN */
@@ -201,8 +212,9 @@ static int mpc_read(struct mpc_i2c *i2c,
/* Write target address byte - this time with the read flag set */
writeb((target << 1) | 1, i2c->base + MPC_I2C_DR);
- if (i2c_wait(i2c, timeout, 1) < 0)
- return -1;
+ ret = i2c_wait(i2c, timeout, 1);
+ if (ret < 0)
+ return ret;
if (length) {
if (length == 1)
@@ -214,8 +226,9 @@ static int mpc_read(struct mpc_i2c *i2c,
}
for (i = 0; i < length; i++) {
- if (i2c_wait(i2c, timeout, 0) < 0)
- return -1;
+ ret = i2c_wait(i2c, timeout, 0);
+ if (ret < 0)
+ return ret;
/* Generate txack on next to last byte */
if (i == length - 2)
@@ -246,8 +259,13 @@ static int mpc_xfer(struct i2c_adapter *
return -EINTR;
}
if (time_after(jiffies, orig_jiffies + HZ)) {
- pr_debug("I2C: timeout\n");
- return -EIO;
+ writeccr(i2c, 0);
+
+ /* try one more time before we error */
+ if (readb(i2c->base + MPC_I2C_SR) & CSR_MBB) {
+ pr_debug("I2C: timeout\n");
+ return -EIO;
+ }
}
schedule();
}
@@ -325,6 +343,7 @@ static int fsl_i2c_probe(struct platform
goto fail_irq;
}
+ writeccr(i2c, 0);
mpc_i2c_setclock(i2c);
platform_set_drvdata(pdev, i2c);
_
Patches currently in -mm which might be from galak@xxxxxxxxxxxxxxxxxxx are
spi-added-spi-master-driver-for.patch
i2c-add-support-for-virtual-i2c-adapters.patch
i2c-pca954x-i2c-mux-driver.patch
i2c-mpc-fix-up-error-handling.patch
pci-pci-64-bit-resources-arch-changes-update.patch
-
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