[U-Boot] [PATCH 1/6] x86: tsc: Read all ratio bits from MSR_PLATFORM_INFO

Bin Meng bmeng.cn at gmail.com
Tue Aug 1 12:21:31 UTC 2017


On Tue, Aug 1, 2017 at 5:10 PM, Simon Glass <sjg at chromium.org> wrote:
> On 25 July 2017 at 21:12, Bin Meng <bmeng.cn at gmail.com> wrote:
>> Currently we read the tsc radio like this:
>>
>>         ratio = (MSR_PLATFORM_INFO >> 8) & 0x1f;
>>
>> Thus we get bit 8-12 of MSR_PLATFORM_INFO, however according to the
>> Intel manual, the ratio bits are bit 8-15.
>>
>> Fix this problem by masking 0xff instead.
>>
>> This keeps in sync with Linux kernel commit:
>>   886123f: x86/tsc: Read all ratio bits from MSR_PLATFORM_INFO
>>
>> Signed-off-by: Bin Meng <bmeng.cn at gmail.com>
>> ---
>>
>>  drivers/timer/tsc_timer.c | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> Reviewed-by: Simon Glass <sjg at chromium.org>

applied to u-boot-x86, thanks!


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