linux-kernel - Re: [PATCH 02/12] drm/nouveau/timer: skip calibration on GK20A

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: <CAAVeFu+pOQq=4nZs_ShVtJrmzhp_TuwNtYxOxGp-1_a2vyNnxQ@mail.gmail.com>
Date:	Tue, 15 Apr 2014 15:10:39 +0900
From:	Alexandre Courbot <gnurou@...il.com>
To:	Ben Skeggs <skeggsb@...il.com>
Cc:	Alexandre Courbot <acourbot@...dia.com>,
	Thierry Reding <thierry.reding@...il.com>,
	"nouveau@...ts.freedesktop.org" <nouveau@...ts.freedesktop.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	"dri-devel@...ts.freedesktop.org" <dri-devel@...ts.freedesktop.org>,
	Ben Skeggs <bskeggs@...hat.com>,
	"linux-tegra@...r.kernel.org" <linux-tegra@...r.kernel.org>
Subject: Re: [PATCH 02/12] drm/nouveau/timer: skip calibration on GK20A

On Mon, Apr 14, 2014 at 5:35 PM, Ben Skeggs <skeggsb@...il.com> wrote:
> On Fri, Apr 11, 2014 at 5:34 PM, Alexandre Courbot <acourbot@...dia.com> wrote:
>> On 04/11/2014 04:31 PM, Ben Skeggs wrote:
>>>
>>> On Fri, Apr 11, 2014 at 12:46 PM, Alexandre Courbot <gnurou@...il.com>
>>> wrote:
>>>>
>>>> On Wed, Mar 26, 2014 at 1:19 PM, Ben Skeggs <skeggsb@...il.com> wrote:
>>>>>
>>>>> On Tue, Mar 25, 2014 at 7:54 AM, Thierry Reding
>>>>> <thierry.reding@...il.com> wrote:
>>>>>>
>>>>>> On Mon, Mar 24, 2014 at 05:42:24PM +0900, Alexandre Courbot wrote:
>>>>>>>
>>>>>>> GK20A's timer is directly attached to the system timer and cannot be
>>>>>>> calibrated. Skip the calibration phase on that chip since the
>>>>>>> corresponding registers do not exist.
>>>>>>>
>>>>>>> Signed-off-by: Alexandre Courbot <acourbot@...dia.com>
>>>>>>> ---
>>>>>>>   drivers/gpu/drm/nouveau/core/subdev/timer/nv04.c | 19
>>>>>>> +++++++++++++------
>>>>>>>   1 file changed, 13 insertions(+), 6 deletions(-)
>>>>>>>
>>>>>>> diff --git a/drivers/gpu/drm/nouveau/core/subdev/timer/nv04.c
>>>>>>> b/drivers/gpu/drm/nouveau/core/subdev/timer/nv04.c
>>>>>>> index c0bdd10358d7..822fe0d8a871 100644
>>>>>>> --- a/drivers/gpu/drm/nouveau/core/subdev/timer/nv04.c
>>>>>>> +++ b/drivers/gpu/drm/nouveau/core/subdev/timer/nv04.c
>>>>>>> @@ -185,6 +185,10 @@ nv04_timer_init(struct nouveau_object *object)
>>>>>>>        if (ret)
>>>>>>>                return ret;
>>>>>>>
>>>>>>> +     /* gk20a does not have the calibration registers */
>>>>>>> +     if (device->chipset == 0xea)
>>>>>>> +             goto skip_clk_init;
>>>>>>
>>>>>>
>>>>>> I'm concerned that this won't scale in the future. Perhaps a better
>>>>>> solution would be to add a "flags" or "features" field to struct
>>>>>> nouveau_device along with feature bits such as HAS_CALIBRATION or
>>>>>> similar.
>>>>>>
>>>>>> That way we don't have to touch this code for every new future Tegra
>>>>>> chip. Unless perhaps if there's a reason to expect things to change in
>>>>>> newer generations.
>>>>>
>>>>> I've already handled this in a slightly different way in the tree I'd
>>>>> previously pointed Alex at (I think!), as I needed to do the same for
>>>>> GM107.
>>>>>
>>>>> Should just be able to use that implementation (so, just change the
>>>>> probe patch) here too.
>>>>
>>>>
>>>> I will skip this patch and use your implementation then. Btw,
>>>> shouldn't the source file for the GK20A implementation be named nvea.c
>>>> instead of gk20a.c?
>>>
>>> For the Maxwell stuff I've been using "gm107" now too.  Since we're
>>> working with you guys these days it seems better to use the same names
>>> for things ;)
>>
>>
>> So would you like us to use the same naming scheme as well? So far all my
>> patches use "nvea.c" whenever I need to add code.
> If it's not too much of a problem at this point, then that'd be good.
> Right before I send -next for the next merge window I'll likely do a
> mass rename anyway, so if we can get your patches merged before then
> (which would be really good!), it doesn't matter much.

No problem, I will update the naming to follow what you did with the
timer driver and gm107.

Hopefully I will soon manage to carve out some time to rebase these
patches and send v2.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/