From: Thomas Kavanagh <tkavanagh@xxxxxxxxxxx>
The parameter passed to pca9665_reset is adap->data (which is bus driver
specific), not i2c_algp_pca_data *adap. pca9665_reset expects it to be
i2c_algp_pca_data *adap. All other wrappers from the algo call back to
the bus driver, which knows to handle its custom data. Only pca9665_reset
resides inside the algorithm code and does not know how to handle a custom
data structure. This can result in a kernel crash.
Fix by re-factoring pca_reset() from a macro to a function handling chip
specific code, and only call adap->reset_chip() if the chip is not PCA9665.
Cc: Wolfram Sang <w.sang@xxxxxxxxxxxxxx>
Signed-off-by: Thomas Kavanagh <tkavanagh@xxxxxxxxxxx>
Signed-off-by: Guenter Roeck <groeck@xxxxxxxxxxx>
---
v2: Improve patch description
Wolfram, if there is anything else you are looking for (more detailed
explanation, maybe ?), please let us know.
drivers/i2c/algos/i2c-algo-pca.c | 27 ++++++++++++++-------------
include/linux/i2c-algo-pca.h | 1 +
2 files changed, 15 insertions(+), 13 deletions(-)
diff --git a/drivers/i2c/algos/i2c-algo-pca.c b/drivers/i2c/algos/i2c-algo-pca.c
index 73133b1..07ccbef 100644
--- a/drivers/i2c/algos/i2c-algo-pca.c
+++ b/drivers/i2c/algos/i2c-algo-pca.c
@@ -46,14 +46,19 @@ static int i2c_debug;
#define pca_set_con(adap, val) pca_outw(adap, I2C_PCA_CON, val)
#define pca_get_con(adap) pca_inw(adap, I2C_PCA_CON)
#define pca_wait(adap) adap->wait_for_completion(adap->data)
-#define pca_reset(adap) adap->reset_chip(adap->data)
-static void pca9665_reset(void *pd)
+static void pca_reset(struct i2c_algo_pca_data *adap)
{
- struct i2c_algo_pca_data *adap = pd;
- pca_outw(adap, I2C_PCA_INDPTR, I2C_PCA_IPRESET);
- pca_outw(adap, I2C_PCA_IND, 0xA5);
- pca_outw(adap, I2C_PCA_IND, 0x5A);
+ if (adap->chip == I2C_PCA_CHIP_9665) {
+ /* Ignore the reset function from the module,
+ * we can use the parallel bus reset.
+ */
+ pca_outw(adap, I2C_PCA_INDPTR, I2C_PCA_IPRESET);
+ pca_outw(adap, I2C_PCA_IND, 0xA5);
+ pca_outw(adap, I2C_PCA_IND, 0x5A);
+ } else {
+ adap->reset_chip(adap->data);
+ }
}
/*
@@ -378,11 +383,12 @@ static unsigned int pca_probe_chip(struct i2c_adapter *adap)
pca_outw(pca_data, I2C_PCA_INDPTR, I2C_PCA_IADR);
if (pca_inw(pca_data, I2C_PCA_IND) == 0xAA) {
printk(KERN_INFO "%s: PCA9665 detected.\n", adap->name);
- return I2C_PCA_CHIP_9665;
+ pca_data->chip = I2C_PCA_CHIP_9665;
} else {
printk(KERN_INFO "%s: PCA9564 detected.\n", adap->name);
- return I2C_PCA_CHIP_9564;
+ pca_data->chip = I2C_PCA_CHIP_9564;
}
+ return pca_data->chip;
}
static int pca_init(struct i2c_adapter *adap)
@@ -456,11 +462,6 @@ static int pca_init(struct i2c_adapter *adap)
*/
int raise_fall_time;
- /* Ignore the reset function from the module,
- * we can use the parallel bus reset
- */
- pca_data->reset_chip = pca9665_reset;
-
if (pca_data->i2c_clock > 1265800) {
printk(KERN_WARNING "%s: I2C clock speed too high."
" Using 1265.8kHz.\n", adap->name);
diff --git a/include/linux/i2c-algo-pca.h b/include/linux/i2c-algo-pca.h
index 1364d62..a3c3ecd 100644
--- a/include/linux/i2c-algo-pca.h
+++ b/include/linux/i2c-algo-pca.h
@@ -62,6 +62,7 @@ struct i2c_algo_pca_data {
* 330000, 288000, 217000, 146000, 88000, 59000, 44000, 36000
* For PCA9665, use the frequency you want here. */
unsigned int i2c_clock;
+ unsigned int chip;
};
int i2c_pca_add_bus(struct i2c_adapter *);
--
1.7.9.7
--
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