Re: [PATCH v7 00/42] ARM: davinci: convert to common clock framework​

[Bartosz Golaszewski]

2018-02-21 18:05 GMT+01:00 David Lechner <david at lechnology.com>:
> On 02/21/2018 06:01 AM, Bartosz Golaszewski wrote:
>>
>> 2018-02-20 19:39 GMT+01:00 David Lechner <david at lechnology.com>:
>>>
>>> On 02/20/2018 07:33 AM, Bartosz Golaszewski wrote:
>>>>
>>>>
>>>> 2018-02-19 21:21 GMT+01:00 David Lechner <david at lechnology.com>:
>>>>>
>>>>>
>>>>> This series converts mach-davinci to use the common clock framework.
>>>>>
>>>>>
>>>>
>>>> Hi David,
>>>>
>>>> just some quick results from today's playing with v7.
>>>>
>>>> I started out with da850-lcdk with my standard rootfs over NFS. I was
>>>> not able to boot to console so far. The first problem is that mdio
>>>> fails to probe:
>>>>
>>>> libphy: Fixed MDIO Bus: probed
>>>> davinci_mdio 1e24000.mdio: davinci mdio revision 1.5, bus freq 2200000
>>>> davinci_mdio 1e24000.mdio: no live phy, scanning all
>>>> davinci_mdio: probe of 1e24000.mdio failed with error -5> After some
>>>> digging I noticed that the supplied clock rate differs
>>>> between mainline (114000000Hz) vs common-clock-v7 (18000000). Since
>>>> we're not setting the rate in mdio, using LPSC_SET_RATE_PARENT would
>>>> not help like with lcdc.
>>>
>>>
>>>
>>> Can you post the output of this command so that I can see how your
>>> clocks are setup:
>>>
>>> cat /sys/kernel/debug/clk/clk_summary
>>>
>>>
>>>>
>>>> After that, the boot just hangs without ever getting to emac's probe.
>>>
>>>
>>>
>>> Using your workaround, can you run:
>>>
>>> cat /sys/kernel/debug/pm_genpd/pm_genpd_summary
>>>
>>> If you see:
>>>    1e27000.clock-controller: emac  off-0
>>>
>>> then genpd is not working like it is supposed to. You should see
>>> something
>>> like this for device that are working:
>>>            1e27000.clock-controller: uart2  on
>>>      /devices/platform/soc at 1c00000/1d0d000.serial        active
>>>
>>>
>>>>
>>>> Once I set the emac clock to always enabled (a workaround that was
>>>> necessary with v6, but could be dropped with my first
>>>> genpd-in-a-separate-driver attempt), I'm getting a rather strange NULL
>>>> pointer dereference:
>>>
>>>
>>>
>>> I noticed this too when adding the power-domains property to some device
>>> tree nodes. This is part of the reason why I didn't add it everywhere.
>>> I wasn't able to figure out the cause of this yet. As a work around
>>> though, please try removing the power-domains property from the emac
>>> and mdio nodes and use your previous workaround of having an always
>>> enabled clock.
>>>
>>>
>>
>> When I use any of the workarounds I just keep getting more problems
>> (e.g. [1] from blk and pinctrl). I only had a couple hours today to
>> play with it but it seems to me we have some memory corruption
>> somewhere. I'll check the initialization order of all the frameworks
>> involved tomorrow.
>>
>> Best regards,
>> Bartosz
>>
>> [1] https://pastebin.com/75mkkuJL
>>
>
> I wonder if we need to delete all of the __init and __initconst attributes
> now that this has been converted to platform devices.
>

Duh... Of course we do. IIRC everything in the init section gets
removed after late_initcall. I'll test that tomorrow.

Bart