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authorRene Herman <rene.herman@gmail.com>2008-10-14 17:30:03 +0200
committerJean Delvare <khali@mahadeva.delvare>2008-10-14 17:30:03 +0200
commitce5640330b10c6cecfbda50569b9f53c081d10c6 (patch)
tree93a3cbb3ecea9be12b468781b36ea3039724ccb4 /drivers/i2c
parent9df013b3e46c67dd3745df91eaccdc719118e0cc (diff)
downloadlinux-ce5640330b10c6cecfbda50569b9f53c081d10c6.tar.bz2
i2c-pca-isa: Don't grab arbitrary resources
Grabbing ISA bus resources without anything or anyone telling us we should can break boot on randconfig/allyesconfig builds by keeping resources that are in fact owned by different hardware busy and does as reported by Ingo Molnar. Generally it's also dangerous to just poke at random I/O ports and especially those in the range where other old easily confused ISA hardware might live. For this specialized I2C bus driver, insist that the user specifies the resources before grabbing them. The^WA user of this driver is a one time echo "options i2c-pca-isa base=0x330 irq=10" >> /etc/modprobe.conf away from the old behaviour. Signed-off-by: Rene Herman <rene.herman@gmail.com> Signed-off-by: Jean Delvare <khali@linux-fr.org>
Diffstat (limited to 'drivers/i2c')
-rw-r--r--drivers/i2c/busses/i2c-pca-isa.c20
1 files changed, 17 insertions, 3 deletions
diff --git a/drivers/i2c/busses/i2c-pca-isa.c b/drivers/i2c/busses/i2c-pca-isa.c
index a119784bae10..f80df9ae5054 100644
--- a/drivers/i2c/busses/i2c-pca-isa.c
+++ b/drivers/i2c/busses/i2c-pca-isa.c
@@ -36,8 +36,8 @@
#define DRIVER "i2c-pca-isa"
#define IO_SIZE 4
-static unsigned long base = 0x330;
-static int irq = 10;
+static unsigned long base;
+static int irq = -1;
/* Data sheet recommends 59kHz for 100kHz operation due to variation
* in the actual clock rate */
@@ -107,6 +107,19 @@ static struct i2c_adapter pca_isa_ops = {
.timeout = 100,
};
+static int __devinit pca_isa_match(struct device *dev, unsigned int id)
+{
+ int match = base != 0;
+
+ if (match) {
+ if (irq <= -1)
+ dev_warn(dev, "Using polling mode (specify irq)\n");
+ } else
+ dev_err(dev, "Please specify I/O base\n");
+
+ return match;
+}
+
static int __devinit pca_isa_probe(struct device *dev, unsigned int id)
{
init_waitqueue_head(&pca_wait);
@@ -153,7 +166,7 @@ static int __devexit pca_isa_remove(struct device *dev, unsigned int id)
{
i2c_del_adapter(&pca_isa_ops);
- if (irq > 0) {
+ if (irq > -1) {
disable_irq(irq);
free_irq(irq, &pca_isa_ops);
}
@@ -163,6 +176,7 @@ static int __devexit pca_isa_remove(struct device *dev, unsigned int id)
}
static struct isa_driver pca_isa_driver = {
+ .match = pca_isa_match,
.probe = pca_isa_probe,
.remove = __devexit_p(pca_isa_remove),
.driver = {