@@ -125,6 +125,13 @@ static int __devinit r9701_probe(struct spi_device *spi)
unsigned char tmp;
int res;
+ tmp = R100CNT;
+ res = read_regs(&spi->dev, &tmp, 1);
+ if (res || tmp != 0x20) {
+ dev_err(&spi->dev, "cannot read RTC register\n");
+ return -ENODEV;
+ }
+
rtc = rtc_device_register("r9701",
&spi->dev, &r9701_rtc_ops, THIS_MODULE);
if (IS_ERR(rtc))
@@ -132,13 +139,6 @@ static int __devinit r9701_probe(struct spi_device *spi)
dev_set_drvdata(&spi->dev, rtc);
- tmp = R100CNT;
- res = read_regs(&spi->dev, &tmp, 1);
- if (res || tmp != 0x20) {
- rtc_device_unregister(rtc);
- return res;
- }
-
return 0;
}
If probing the RTC didn't succeed due to failed RTC register access, the RTC device will be unregistered. Then, when removing the module r9701_remove() causes kernel crash while trying to unregister not registered RTC device. Fix this by doing RTC register access test before RTC device registration. Signed-off-by: Anatolij Gustschin <agust@denx.de> Cc: Alessandro Zummo <a.zummo@towertech.it> --- drivers/rtc/rtc-r9701.c | 14 +++++++------- 1 files changed, 7 insertions(+), 7 deletions(-)