RE: [Patch 0/1]drm_irq: Introducing the irq_thread support

[Shi, Yang A]

Hi Vetter:

    Do you mean we can just not use drm_irq_install, and make request_irq in our kernel driver pre-install or post-install interface?






Best Regards.
Yang Shi

PSI,System Integration, SH
E-mail:yang.a.shi@xxxxxxxxx
Tel:88215666-4239


-----Original Message-----
From: Daniel Vetter [mailto:daniel.vetter@xxxxxxxx] On Behalf Of Daniel Vetter
Sent: Wednesday, September 05, 2012 9:27 PM
To: Liu, Chuansheng
Cc: 'linux-kernel@xxxxxxxxxxxxxxx' (linux-kernel@xxxxxxxxxxxxxxx); dri-devel@xxxxxxxxxxxxxxxxxxxxx; alexander.deucher@xxxxxxx; airlied@xxxxxxxxxx; Shi, Yang A
Subject: Re: [Patch 0/1]drm_irq: Introducing the irq_thread support

On Wed, Sep 05, 2012 at 01:53:44AM +0000, Liu, Chuansheng wrote:
> This patch is for introducing the irq thread support in drm_irq.
> 
> Why we need irq thread in drm_irq code?
> In our GPU system, the gpu interrupt handler need some time even > 1ms 
> to finish, in that case, the whole system will stay in irq disable status. One case is:
> when audio is playing, it sometimes effects the audio quality.
> 
> So we have to introduce the irq thread in drm_irq, it can help us move 
> some heavy work into irq thread and other irq interrupts can be handled in time. Also the IRQF_ONESHOT is helpful for irq thread.
> 
> Include one patch:
> [PATCH 01/1] drm_irq-Introducing-the-irq_thread-support

For a kms drm driver (and tbh, doing a non-kms driver today is not a great idea), there's no reason to use the drm_irq_install/_unistall helpers.

So if you driver has special needs wrt irq handling that don't neatly fit what the drm_irq stuff provides, simply don't use it - all the generic code that's there is just to keep non-kms userspace going.

Yours, Daniel
--
Daniel Vetter
Mail: daniel@xxxxxxxx
Mobile: +41 (0)79 365 57 48
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