Commit-ID: 16c21ae5ca636cfd38e581ebcf709c49d78ea56d Gitweb: http://git.kernel.org/tip/16c21ae5ca636cfd38e581ebcf709c49d78ea56d Author: Li Fei <fei...@intel.com> AuthorDate: Wed, 21 Aug 2013 16:13:57 +0800 Committer: Ingo Molnar <mi...@kernel.org> CommitDate: Wed, 25 Sep 2013 19:33:22 +0200
reboot: Allow specifying warm/cold reset for CF9 boot type In current implementation for reboot type CF9 and CF9_COND, warm and cold reset are not differentiated, and both are performed by writing 0x06 to port 0xCF9. This commit will differentiate warm and cold reset: For warm reset, write 0x06 to port 0xCF9; For cold reset, write 0x0E to port 0xCF9. [ hpa: This meaning of "cold" and "warm" reset is different from other reboot types use, where "warm" means "bypass BIOS POST". It is also not entirely clear that it actually solves any actual problem. However, it would seem fairly harmless to offer this additional option. Also note that we do not mask bit 3 in the "warm reset" case. This preserves the behavior on existing systems, including ones quirked to use CF9. It seems reasonable that on any system where the warm/cold distinction actually matters that bit 3 would be read as zero. ] From: Liu Chuansheng <chuansheng....@intel.com> Signed-off-by: Li Fei <fei...@intel.com> Link: http://lkml.kernel.org/r/1377072837.24556.2.camel@fli24-HP-Compaq-8100-Elite-CMT-PC Signed-off-by: H. Peter Anvin <h...@linux.intel.com> Signed-off-by: Ingo Molnar <mi...@kernel.org> --- arch/x86/kernel/reboot.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/reboot.c b/arch/x86/kernel/reboot.c index 563ed91..ca42f63 100644 --- a/arch/x86/kernel/reboot.c +++ b/arch/x86/kernel/reboot.c @@ -511,10 +511,13 @@ static void native_machine_emergency_restart(void) case BOOT_CF9_COND: if (port_cf9_safe) { - u8 cf9 = inb(0xcf9) & ~6; + u8 reboot_code = reboot_mode == REBOOT_WARM ? + 0x06 : 0x0E; + u8 cf9 = inb(0xcf9) & ~reboot_code; outb(cf9|2, 0xcf9); /* Request hard reset */ udelay(50); - outb(cf9|6, 0xcf9); /* Actually do the reset */ + /* Actually do the reset */ + outb(cf9|reboot_code, 0xcf9); udelay(50); } reboot_type = BOOT_KBD; -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
