Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752073AbaAXR3V (ORCPT ); Fri, 24 Jan 2014 12:29:21 -0500 Received: from mail-ea0-f174.google.com ([209.85.215.174]:59480 "EHLO mail-ea0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751293AbaAXR3U (ORCPT ); Fri, 24 Jan 2014 12:29:20 -0500 Message-ID: <52E2A2E8.50806@gmail.com> Date: Fri, 24 Jan 2014 18:29:12 +0100 From: Sebastian Hesselbarth User-Agent: Mozilla/5.0 (X11; Linux i686; rv:24.0) Gecko/20100101 Thunderbird/24.0 To: Russell King - ARM Linux , Jean-Francois Moine CC: dri-devel@lists.freedesktop.org, Dave Airlie , Rob Clark , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v3 15/24] drm/i2c: tda998x: use irq for connection status and EDID read References: <20140119195843.7ae9753d@armhf> <20140122222705.GL15937@n2100.arm.linux.org.uk> In-Reply-To: <20140122222705.GL15937@n2100.arm.linux.org.uk> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 01/22/14 23:27, Russell King - ARM Linux wrote: > On Sun, Jan 19, 2014 at 07:58:43PM +0100, Jean-Francois Moine wrote: >> This patch adds the optional treatment of the tda998x IRQ. >> >> The interrupt function is used to know the display connection status >> without polling and to speedup reading the EDID. >> >> The interrupt number may be defined either in the DT or at encoder set >> config time for non-DT boards. >> >> Signed-off-by: Jean-Francois Moine >> --- [...] >> @@ -720,6 +787,10 @@ tda998x_encoder_set_config(struct drm_encoder *encoder, void *params) >> priv->audio_port = p->audio_cfg; >> priv->audio_format = p->audio_format; >> } >> + >> + priv->irq = p->irq; >> + if (p->irq) >> + tda_irq_init(priv); > > If we're going to do it this way, this should probably release the IRQ if > there was one before re-claiming it, just in case this function gets called > more than once by some driver using it. > > The alternative is, as I said before, to use the infrastructure which is > already there, namely setting the interrupt via struct i2c_client's > irq member. Yes, that doesn't satisfy Sebastian's comment about using > a GPIO, but there's no sign of GPIO usage in here at the moment anyway. > So we might as well use what's already provided. Russell, I am fine with using an irq instead of gpio here. I remember you telling me on a similar patch, that from the gpio you can derive the irq but not the other way round. Anyway, I also remember reading discussions about DT gpios vs interrupts, and IIRC the outcome was that passing interrupts is fine, too. We usually have both interrupt-controller; and gpio-controller; set on DT gpio controllers, so let's stick with irq. And: Thanks for reviewing this again, I am still too busy to keep up with it. Sebastian -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/