The patch titled rtc: fall back to requesting only the ports we actually use has been removed from the -mm tree. Its filename was rtc-fallback-to-requesting-only-the-ports-we-actually-use.patch This patch was dropped because it was merged into mainline or a subsystem tree ------------------------------------------------------ Subject: rtc: fall back to requesting only the ports we actually use From: Bjorn Helgaas <bjorn.helgaas@xxxxxx> Firmware like PNPBIOS or ACPI can report the address space consumed by the RTC. The actual space consumed may be less than the size (RTC_IO_EXTENT) assumed by the RTC driver. The PNP core doesn't request resources yet, but I'd like to make it do so. If/when it does, the RTC_IO_EXTENT request may fail, which prevents the RTC driver from loading. Since we only use the RTC index and data registers at RTC_PORT(0) and RTC_PORT(1), we can fall back to requesting just enough space for those. If the PNP core requests resources, this results in typical I/O port usage like this: 0070-0073 : 00:06 <-- PNP device 00:06 responds to 70-73 0070-0071 : rtc <-- RTC driver uses only 70-71 instead of the current: 0070-0077 : rtc <-- RTC_IO_EXTENT == 8 Signed-off-by: Bjorn Helgaas <bjorn.helgaas@xxxxxx> Cc: Alessandro Zummo <a.zummo@xxxxxxxxxxxx> Cc: David Brownell <david-b@xxxxxxxxxxx> Cc: Ralf Baechle <ralf@xxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- drivers/char/rtc.c | 36 ++++++++++++++++++++++++++++------ include/linux/mc146818rtc.h | 3 ++ 2 files changed, 33 insertions(+), 6 deletions(-) diff -puN drivers/char/rtc.c~rtc-fallback-to-requesting-only-the-ports-we-actually-use drivers/char/rtc.c --- a/drivers/char/rtc.c~rtc-fallback-to-requesting-only-the-ports-we-actually-use +++ a/drivers/char/rtc.c @@ -918,12 +918,29 @@ static const struct file_operations rtc_ }; #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 -puN include/linux/mc146818rtc.h~rtc-fallback-to-requesting-only-the-ports-we-actually-use include/linux/mc146818rtc.h --- a/include/linux/mc146818rtc.h~rtc-fallback-to-requesting-only-the-ports-we-actually-use +++ a/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 */ _ Patches currently in -mm which might be from bjorn.helgaas@xxxxxx are origin.patch small-acpica-extension-to-be-able-to-store-the-name-of.patch export-acpi_check_resource_conflict.patch mm-only-enforce-acpi-resource-conflict-checks.patch serial-keep-the-dtr-setting-for-serial-console.patch rtc-cmos-exports-nvram-in-sysfs.patch pnp-simplify-pnp_activate_dev-and-pnp_disable_dev-return-values.patch pnp-request-ioport-and-iomem-resources-used-by-active-devices.patch dont-touch-fs_struct-in-drivers.patch - To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html