[PATCH 2/2] arch_timer: acpi: add hisi timer erratum data

[Ding Tianhong]

On 2017/2/21 3:00, Marc Zyngier wrote:
> On 10/02/17 07:10, Hanjun Guo wrote:
>> Hi Marc,
>>
>> On 2017/1/24 19:32, Marc Zyngier wrote:
>>> On 24/01/17 10:57, Mark Rutland wrote:
>>>> On Tue, Jan 24, 2017 at 06:39:51PM +0800, Hanjun Guo wrote:
>>>>> From: Hanjun Guo <hanjun.guo at linaro.org>
>>>>>
>>>>> Add hisilicon timer specific erratum fixes.
>>>>>
>>>>> Signed-off-by: Hanjun Guo <hanjun.guo at linaro.org>
>>>>> ---
>>>>>  drivers/clocksource/arm_arch_timer.c | 22 ++++++++++++++++++++++
>>>>>  1 file changed, 22 insertions(+)
>>>>>
>>>>> diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c
>>>>> index 80d6f76..3e62a09 100644
>>>>> --- a/drivers/clocksource/arm_arch_timer.c
>>>>> +++ b/drivers/clocksource/arm_arch_timer.c
>>>>> @@ -1156,10 +1156,32 @@ struct gtdt_arch_timer_fixup {
>>>>>  	void *context;
>>>>>  };
>>>>>  
>>>>> +#ifdef CONFIG_HISILICON_ERRATUM_161010101
>>>>> +static void __init hisi_erratum_workaroud_enable(void *context)
>>>>> +{
>>>>> +	int i;
>>>>> +
>>>>> +	for (i = 0; i < ARRAY_SIZE(ool_workarounds); i++) {
>>>>> +		if (!strcmp(context, ool_workarounds[i].id)) {
>>>>> +			timer_unstable_counter_workaround = &ool_workarounds[i];
>>>>> +			static_branch_enable(&arch_timer_read_ool_enabled);
>>>>> +			pr_info("arch_timer: Enabling workaround for %s\n",
>>>>> +				timer_unstable_counter_workaround->id);
>>>>> +			break;
>>>>> +		}
>>>>> +	}
>>>>> +}
>>>>> +#endif
>>>>> +
>>>>>  /* note: this needs to be updated according to the doc of OEM ID
>>>>>   * and TABLE ID for different board.
>>>>>   */
>>>>>  static struct gtdt_arch_timer_fixup arch_timer_quirks[] __initdata = {
>>>>> +#ifdef CONFIG_HISILICON_ERRATUM_161010101
>>>>> +	{"HISI  ", "HIP05   ", 0, &hisi_erratum_workaroud_enable, "hisilicon,erratum-161010101"},
>>>>> +	{"HISI  ", "HIP06   ", 0, &hisi_erratum_workaroud_enable, "hisilicon,erratum-161010101"},
>>>>> +	{"HISI  ", "HIP07   ", 0, &hisi_erratum_workaroud_enable, "hisilicon,erratum-161010101"},
>>>>> +#endif
>>>>>  };
>>>> NAK. This duplicates logic unnecessarily (for enabling the workaround),
>>>> and (ab)uses the id, which was intended to be specific to DT (since it
>>>> is a DT property name).
>>> Agreed, that's properly revolting.
>>>
>>>> We should split the matching from the particular workaround (and
>>>> enabling thereof), so that we can go straight from ACPI match to
>>>> workaround (without having to use the DT id in this manner), and don't
>>>> have to duplicate the logic to enable the workaround.
>>>>
>>>> I believe Marc is looking at some rework in this area which may enable
>>>> this, so please wait for that to appear.
>>> Yeah, I'm implementing a semi-flexible way to add new quirk types, and
>>> the last thing I want to see is two (or more) tables describing the same
>>> thing.
>>
>> Kindly ping, if you have patches in hand, I can test against our platforms,
>> thank you very much.
> 
> I've just pushed out a branch based on arm64/for-next/core, plus the
> HiSi timer workaround:
> 
> https://git.kernel.org/cgit/linux/kernel/git/maz/arm-platforms.git/log/?h=timers/errata-rework
> 
> I'll post the patches for review once the merge window is open, but
> hopefully that should get you going.
> 
> Thanks,
> 


Test this branch and could work fine for Hisilicon board, great work !

Still need time to review the details, but this should not seem very difficult. :)

Thanks
Ding

> 	M.
>