diff options
| -rw-r--r-- | drivers/char/rtc.c | 36 | ||||
| -rw-r--r-- | include/linux/mc146818rtc.h | 3 |
2 files changed, 33 insertions, 6 deletions
diff --git a/drivers/char/rtc.c b/drivers/char/rtc.c index a162e1b3d5d..0c66b802736 100644 --- a/drivers/char/rtc.c +++ b/drivers/char/rtc.c @@ -918,12 +918,29 @@ static const struct file_operations rtc_proc_fops = { }; #endif +static resource_size_t rtc_size; + +static struct resource * __init rtc_request_region(resource_size_t size) +{ + struct resource *r; + + if (RTC_IOMAPPED) + r = request_region(RTC_PORT(0), size, "rtc"); + else + r = request_mem_region(RTC_PORT(0), size, "rtc"); + + if (r) + rtc_size = size; + + return r; +} + static void rtc_release_region(void) { if (RTC_IOMAPPED) - release_region(RTC_PORT(0), RTC_IO_EXTENT); + release_region(RTC_PORT(0), rtc_size); else - release_mem_region(RTC_PORT(0), RTC_IO_EXTENT); + release_mem_region(RTC_PORT(0), rtc_size); } static int __init rtc_init(void) @@ -976,10 +993,17 @@ found: } no_irq: #else - if (RTC_IOMAPPED) - r = request_region(RTC_PORT(0), RTC_IO_EXTENT, "rtc"); - else - r = request_mem_region(RTC_PORT(0), RTC_IO_EXTENT, "rtc"); + r = rtc_request_region(RTC_IO_EXTENT); + + /* + * If we've already requested a smaller range (for example, because + * PNPBIOS or ACPI told us how the device is configured), the request + * above might fail because it's too big. + * + * If so, request just the range we actually use. + */ + if (!r) + r = rtc_request_region(RTC_IO_EXTENT_USED); if (!r) { #ifdef RTC_IRQ rtc_has_irq = 0; diff --git a/include/linux/mc146818rtc.h b/include/linux/mc146818rtc.h index 580b3f4956e..2f4e957af65 100644 --- a/include/linux/mc146818rtc.h +++ b/include/linux/mc146818rtc.h @@ -109,8 +109,11 @@ struct cmos_rtc_board_info { #ifndef ARCH_RTC_LOCATION /* Override by <asm/mc146818rtc.h>? */ #define RTC_IO_EXTENT 0x8 +#define RTC_IO_EXTENT_USED 0x2 #define RTC_IOMAPPED 1 /* Default to I/O mapping. */ +#else +#define RTC_IO_EXTENT_USED RTC_IO_EXTENT #endif /* ARCH_RTC_LOCATION */ #endif /* _MC146818RTC_H */ |