Re: [PATCH v5 01/44] dt-bindings: clock: Add new bindings for TI Davinci PLL clocks

[Adam Ford]

On Thu, Jan 11, 2018 at 3:04 PM, David Lechner <david@xxxxxxxxxxxxxx> wrote:
> On 01/11/2018 02:58 PM, Adam Ford wrote:
>>
>> On Thu, Jan 11, 2018 at 2:04 PM, David Lechner <david@xxxxxxxxxxxxxx>
>> wrote:
>>>
>>> On 01/11/2018 12:50 PM, Adam Ford wrote:
>>>>
>>>>
>>>> On Thu, Jan 11, 2018 at 12:29 PM, David Lechner <david@xxxxxxxxxxxxxx>
>>>> wrote:
>>>>>
>>>>>
>>>>> If removing the "clk_ignore_unused" option causes the board to not
>>>>> boot,
>>>>> then we still have problems that need to be fixed, so please also test
>>>>> without this option.
>>>>
>>>>
>>>>
>>>> Without this option, it still does not boot.  Without device tree it
>>>> hangs after:
>>>>
>>>> [snip]
>>>>
>>>> NET: Registered protocol family 17
>>>> Loading compiled-in X.509 certificates
>>>> console [netcon0] enabled
>>>> netconsole: network logging started
>>>> davinci_emac davinci_emac.1: using random MAC addr: 5e:38:1a:1f:4f:77
>>>> mmc0: host does not support reading read-only switch, assuming
>>>> write-enable
>>>> hctosys: unable to open rtc device (rtc0)
>>>> mmc0: new high speed SDHC card at address b368
>>>>
>>>>
>>>> With device tree it hangs after:
>>>>
>>>> [snip]
>>>> mmc0: host does not support reading read-only switch, assuming
>>>> write-enable
>>>> mmc0: new high speed SDHC card at address b368
>>>> mmcblk0: mmc0:b368 00000 3.75 GiB
>>>>    mmcblk0: p1 p2
>>>> pca953x 0-0020: 0-0020 supply vcc not found, using dummy regulator
>>>> pca953x 0-0020: failed reading register
>>>> pca953x: probe of 0-0020 failed with error -121
>>>> console [netcon0] enabled
>>>> netconsole: network logging started
>>>> davinci_emac 1e20000.ethernet: incompatible machine/device type for
>>>> reading mac address
>>>> hctosys: unable to open rtc device (rtc0)
>>>>
>>>>
>>>
>>> Please try this change:
>>>
>>> diff --git a/drivers/clk/davinci/psc-da850.c
>>> b/drivers/clk/davinci/psc-da850.c
>>> index 3fd6b49..a526cc2 100644
>>> --- a/drivers/clk/davinci/psc-da850.c
>>> +++ b/drivers/clk/davinci/psc-da850.c
>>> @@ -17,7 +17,7 @@ static const struct davinci_psc_clk_info
>>> da850_psc0_info[]
>>> __initconst = {
>>>          LPSC(0, 0, tpcc0, pll0_sysclk2, LPSC_ALWAYS_ENABLED),
>>>          LPSC(1, 0, tptc0, pll0_sysclk2, LPSC_ALWAYS_ENABLED),
>>>          LPSC(2, 0, tptc1, pll0_sysclk2, LPSC_ALWAYS_ENABLED),
>>> -       LPSC(3, 0, aemif, pll0_sysclk3, 0),
>>> +       LPSC(3, 0, aemif, pll0_sysclk3, LPSC_ALWAYS_ENABLED),
>>>          LPSC(4, 0, spi0, pll0_sysclk2, 0),
>>>          LPSC(5, 0, mmcsd0, pll0_sysclk2, 0),
>>>          LPSC(6, 0, aintc, pll0_sysclk4, LPSC_ALWAYS_ENABLED),
>>>
>>>
>>>
>>> If that does not work, try adding LPSC_ALWAYS_ENABLED to all of the
>>> clocks
>>> in this file and then eliminate them one by one until you find which one
>>> is
>>> preventing boot.
>>>
>> Unfortunately, that didn't work.  I switch all the entries in both
>> tables that had a 0 to LPSC_ALWAYS_ENABLED, but no luck booting.
>>
>>> If it still does not boot, there is a similar DIVCLK_ALWAYS_ENABLED flag
>>> in
>>> drivers/clk/davinci/pll-da850.c that you can repeat the exercise with.
>>> Add
>>> DIVCLK_ALWAYS_ENABLED to all of the clocks there and then eliminate it
>>> one
>>> by one until you find the clock that is causing the problem.
>>
>>
>> Still no good news.  I switched all the entries with a 0 to
>> DIVCLK_ALWAYS_ENABLED and it still didn't finish booting.
>>
>> I wonder if Sekhar Nori might have some suggestions.  I didn't look at
>> the code or try to understand it.  I just changed the settings.
>>>
>>>
>
> Even if a clock had another flag besides zero, you will need to add
> LPSC_ALWAYS_ENABLED by or-ing it with the other flag.
>

[snip]


Thanks for clarifying.  I was able to make it work with the following patch:

diff --git a/drivers/clk/davinci/psc-da850.c b/drivers/clk/davinci/psc-da850.c
index 3b4583d..a76b8682 100644
--- a/drivers/clk/davinci/psc-da850.c
+++ b/drivers/clk/davinci/psc-da850.c
@@ -25,7 +25,7 @@ static const struct davinci_psc_clk_info
da850_psc0_info[] __initconst = {
        LPSC(9, 0, uart0, pll0_sysclk2, 0),
        LPSC(13, 0, pruss, pll0_sysclk2, 0),
        LPSC(14, 0, arm, pll0_sysclk6, LPSC_ALWAYS_ENABLED),
-       LPSC(15, 1, dsp, pll0_sysclk1, LPSC_FORCE | LPSC_LOCAL_RESET),
+       LPSC(15, 1, dsp, pll0_sysclk1, LPSC_FORCE | LPSC_LOCAL_RESET |
LPSC_ALWAYS_ENABLED),
        { }
 };


If you have an updated patch series with those two fixes, I add my
name to the tested-by list.


>
>
[snip]
>