linux-kernel - Re: [PATCHv2] clocksource: dw_apb_timer_of: add error handling if no clock available

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Date:   Sat, 5 Dec 2020 11:55:57 +0100
From:   Daniel Lezcano <daniel.lezcano@...aro.org>
To:     Dinh Nguyen <dinguyen@...nel.org>
Cc:     linux-kernel@...r.kernel.org, tglx@...utronix.de,
        Jisheng.Zhang@...aptics.com, arnd@...db.de
Subject: Re: [PATCHv2] clocksource: dw_apb_timer_of: add error handling if no
 clock available

On 05/12/2020 11:55, Dinh Nguyen wrote:
> Hi Daniel,
> 
> On 12/5/20 2:50 AM, Daniel Lezcano wrote:
>> On 04/12/2020 23:39, Dinh Nguyen wrote:
>>>
>>>
>>> On 12/4/20 2:00 PM, Daniel Lezcano wrote:
>>>> On 04/12/2020 16:36, Dinh Nguyen wrote:
>>>>> commit ("b0fc70ce1f02 arm64: berlin: Select DW_APB_TIMER_OF") added
>>>>> the
>>>>> support for the dw_apb_timer into the arm64 defconfig. However, for
>>>>> some
>>>>> platforms like the Intel Stratix10 and Agilex, the clock manager
>>>>> doesn't
>>>>> get loaded until after the timer driver get loaded. Thus, the driver
>>>>> hits
>>>>> the panic "No clock nor clock-frequency property for" because it
>>>>> cannot
>>>>> properly get the clock.
>>>>>
>>>>> This patch adds the error handling needed for the timer driver so that
>>>>> the kernel can continue booting instead of just hitting the panic.
>>>>>
>>>>> Signed-off-by: Dinh Nguyen <dinguyen@...nel.org>
>>>>
>>>> Did you have time to test the different combinations ?
>>>
>>> I did test both versions and did not see any difference between the two.
>>> On both versions, the kernel was able to continue to boot after trying
>>> to probe the timer driver.
>>
>> Great, thanks!
>>
> 
> I forgot to test this on ARM 32-bit system that actually uses one of
> these timers as a clocksource. The v2 patch would fail. The return of
> PTR_ERR(timer_clk) needs an IS_ERR(timer_clk) check.
> 
> I have sent a v3.
> 
> Sorry about that.

No problem, thanks for resending.


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