From: Tero Kristo <t-kristo@ti.com>
To: Tomi Valkeinen <tomi.valkeinen@ti.com>, Adam Ford <aford173@gmail.com>
Cc: "Tony Lindgren" <tony@atomide.com>,
Linux-OMAP <linux-omap@vger.kernel.org>,
"Adam Ford" <adam.ford@logicpd.com>,
"Benoît Cousson" <bcousson@baylibre.com>,
dri-devel <dri-devel@lists.freedesktop.org>,
devicetree <devicetree@vger.kernel.org>,
"Linux Kernel Mailing List" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] drm/omap: Migrate minimum FCK/PCK ratio from Kconfig to dts
Date: Fri, 27 Sep 2019 18:37:35 +0300 [thread overview]
Message-ID: <36369388-e9c8-22cd-8c19-e2bdf2d0389b@ti.com> (raw)
In-Reply-To: <0473526e-df0a-94a5-5c22-debd0084ab16@ti.com>
On 27/09/2019 16:47, Tomi Valkeinen wrote:
> On 27/09/2019 15:33, Adam Ford wrote:
>
>>> It looks like a bug in omap clock handling.
>>>
>>> DSS uses dss1_alwon_fck_3430es2 as fclk. dss1_alwon_fck_3430es2 comes
>>> from dpll4_ck, and there's a divider after the PLL, dpll4_m4_ck.
>>>
>>> When the DSS driver sets dss1_alwon_fck_3430es2 rate to 27000000 or
>>> 27870967, which can be created with m4 dividers 32 and 31, it looks like
>>> the divider goes to bypass, or to a very small value. DSS gets a very
>>> high clock rate and breaks down.
>>
>> Is there anything I can do to help troubleshoot this? I could insert
>> a hack that checks if we're omap3 and if so make the divider equal to
>> 4, but that seems like just a hack.
>> I can run more tests or insert code somewhere if you want.
>
> I think it's up to someone who's knowledgeable in omap clock framework.
> I'm kind of hoping that Tero or Tony would be willing to debug =). I can
> try to find time to debug the omap clk framework, but I'll be going on
> blindly there.
If you can provide details about what clock framework / driver does
wrong (sample clk_set_xyz call sequence, expected results via
clk_get_xyz, and what fails), I can take a look at it. Just reporting
arbitrary display driver issues I won't be able to debug at all (I don't
have access to any of the displays, nor do I want to waste time
debugging them without absolutely no knowledge whatsoever.)
-Tero
--
Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki. Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki
next prev parent reply other threads:[~2019-09-27 15:37 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-10 19:42 [PATCH] drm/omap: Migrate minimum FCK/PCK ratio from Kconfig to dts Adam Ford
2019-05-28 11:11 ` Tomi Valkeinen
2019-05-28 15:09 ` Adam Ford
2019-05-28 15:20 ` H. Nikolaus Schaller
2019-05-28 15:53 ` Tomi Valkeinen
2019-05-31 12:13 ` Adam Ford
2019-09-25 20:51 ` Adam Ford
2019-09-26 6:55 ` Tomi Valkeinen
2019-09-26 14:12 ` Adam Ford
2019-09-27 6:21 ` Tomi Valkeinen
2019-09-27 12:13 ` Adam Ford
2019-09-27 13:45 ` Tomi Valkeinen
2019-09-27 7:55 ` Tomi Valkeinen
2019-09-27 12:33 ` Adam Ford
2019-09-27 13:47 ` Tomi Valkeinen
2019-09-27 15:37 ` Tero Kristo [this message]
2019-09-27 15:47 ` Tomi Valkeinen
2019-09-30 6:45 ` Tomi Valkeinen
2019-09-30 8:53 ` Tero Kristo
2019-09-30 12:41 ` Adam Ford
2019-09-30 12:47 ` Tero Kristo
2019-09-30 13:17 ` Adam Ford
2019-09-30 13:35 ` Tomi Valkeinen
2019-09-30 13:38 ` H. Nikolaus Schaller
2019-09-30 13:54 ` Adam Ford
2019-09-30 14:04 ` Adam Ford
2019-09-30 14:12 ` Adam Ford
2019-09-30 14:20 ` Tomi Valkeinen
2019-09-30 14:27 ` Tomi Valkeinen
2019-09-30 14:56 ` H. Nikolaus Schaller
2019-09-30 15:10 ` Adam Ford
2019-09-30 17:48 ` Tero Kristo
2019-10-01 5:07 ` Tomi Valkeinen
2019-10-01 5:12 ` Tero Kristo
2019-10-01 8:12 ` Tero Kristo
2019-10-01 9:31 ` Tomi Valkeinen
2019-10-01 13:06 ` Adam Ford
2019-10-01 13:14 ` Tomi Valkeinen
2019-09-25 21:26 ` Andrew F. Davis
2019-06-13 20:22 ` Rob Herring
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