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SubjectRe: [PATCH] reboot: perform warm/cold reset correctly for CF9 type
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Careful.  This is a very different definition of warm vs cold boot used elsewhere.

Ingo Molnar <mingo@kernel.org> wrote:
>
>* Li Fei <fei.li@intel.com> wrote:
>
>> 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 as warm reset. It's not
>> correct.
>>
>> This commit will differentiate warm and cold reset, and perform
>> them correctly as below:
>> For warm reset, write 0x06 to port 0xCF9;
>> For cold reset, write 0x0E to port 0xCF9.
>>
>> From: Liu Chuansheng <chuansheng.liu@intel.com>
>> Signed-off-by: Li Fei <fei.li@intel.com>
>> ---
>> arch/x86/kernel/reboot.c | 9 +++++++--
>> 1 files changed, 7 insertions(+), 2 deletions(-)
>>
>> diff --git a/arch/x86/kernel/reboot.c b/arch/x86/kernel/reboot.c
>> index 563ed91..6e06299 100644
>> --- a/arch/x86/kernel/reboot.c
>> +++ b/arch/x86/kernel/reboot.c
>> @@ -511,10 +511,15 @@ static void
>native_machine_emergency_restart(void)
>>
>> case BOOT_CF9_COND:
>> if (port_cf9_safe) {
>> - u8 cf9 = inb(0xcf9) & ~6;
>> + u8 cf9 = inb(0xcf9) &
>> + ~(reboot_mode == REBOOT_WARM ?
>> + 0x06 : 0x0E);
>> outb(cf9|2, 0xcf9); /* Request hard reset */
>> udelay(50);
>> - outb(cf9|6, 0xcf9); /* Actually do the reset */
>> + /* Actually do the reset */
>> + outb(cf9|(reboot_mode == REBOOT_WARM ?
>> + 0x06 : 0x0E),
>> + 0xcf9);
>> udelay(50);
>
>Looks good, but please introduce a reboot_val intermediate
>variable instead of duplicating that ugly line-broken
>construct twice.
>
>Thanks,
>
> Ingo

--
Sent from my mobile phone. Please excuse brevity and lack of formatting.


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