linux-kernel - Re: [PATCH] drm/omap: Migrate minimum FCK/PCK ratio from Kconfig to dts

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <3777f1b1-2d9a-334b-b9e7-99dfda2ae29b@ti.com>
Date:   Mon, 30 Sep 2019 17:27:05 +0300
From:   Tomi Valkeinen <tomi.valkeinen@...com>
To:     Adam Ford <aford173@...il.com>,
        "H. Nikolaus Schaller" <hns@...delico.com>
CC:     Tero Kristo <t-kristo@...com>, Tony Lindgren <tony@...mide.com>,
        Linux-OMAP <linux-omap@...r.kernel.org>,
        Adam Ford <adam.ford@...icpd.com>,
        Benoît Cousson <bcousson@...libre.com>,
        dri-devel <dri-devel@...ts.freedesktop.org>,
        devicetree <devicetree@...r.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] drm/omap: Migrate minimum FCK/PCK ratio from Kconfig to
 dts

On 30/09/2019 17:20, Tomi Valkeinen wrote:

> Let's see what Tero says, but yeah, something is odd here. I expected 
> the max divider to be 16 with Tero's patch, but I don't see it having 
> that effect. I can get the div to 31.
> 
> You can see this from the clock register 0x48004e40 (CM_CLKSEL_DSS). The 
> lowest bits are the divider, 5 to 0. The TRM says max div is 32.
> 
> Tero said for him the dividers > 16 didn't "stick" to the register. I'm 
> now wondering if he has an old beagleboard with OMAP34xx, which has max 
> div 16.

So testing a bit more here, I can see the DSS working fine and fps as 
expected when I write values directly to CM_CLKSEL_DSS:5:0, with 
dividers up to 31. With 32, DSS breaks. The TRM (AM/DM37x) says value 32 
is valid.

  Tomi

-- 
Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki.
Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki