Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755570AbcKVI11 (ORCPT ); Tue, 22 Nov 2016 03:27:27 -0500 Received: from galahad.ideasonboard.com ([185.26.127.97]:33642 "EHLO galahad.ideasonboard.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755472AbcKVI10 (ORCPT ); Tue, 22 Nov 2016 03:27:26 -0500 From: Laurent Pinchart To: John Stultz Cc: lkml , David Airlie , Archit Taneja , Wolfram Sang , Lars-Peter Clausen , "dri-devel@lists.freedesktop.org" Subject: Re: [RFC][PATCH 1/3] drm/bridge: adv7511: Rework adv7511_power_on/off() so they can be reused internally Date: Tue, 22 Nov 2016 10:27:42 +0200 Message-ID: <1926540.Y3AOuWnbYN@avalon> User-Agent: KMail/4.14.10 (Linux/4.8.6-gentoo; KDE/4.14.24; x86_64; ; ) In-Reply-To: References: <1479775052-28194-1-git-send-email-john.stultz@linaro.org> <1961666.AZMl081OYz@avalon> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4755 Lines: 131 Hi John, On Tuesday 22 Nov 2016 00:16:55 John Stultz wrote: > On Tue, Nov 22, 2016 at 12:14 AM, Laurent Pinchart wrote: > > On Monday 21 Nov 2016 16:37:30 John Stultz wrote: > >> In chasing down issues with EDID probing, I found some > >> duplicated but incomplete logic used to power the chip on and > >> off. > >> > >> This patch refactors the adv7511_power_on/off functions, so > >> they can be used for internal needs, and replaces duplicative > >> logic that powers the chip on and off around the EDID probing > >> with the common logic. > >> > >> Cc: David Airlie > >> Cc: Archit Taneja > >> Cc: Wolfram Sang > >> Cc: Lars-Peter Clausen > >> Cc: Laurent Pinchart > >> Cc: dri-devel@lists.freedesktop.org > >> Signed-off-by: John Stultz > >> --- > >> > >> drivers/gpu/drm/bridge/adv7511/adv7511_drv.c | 30 +++++++++------------- > >> 1 file changed, 14 insertions(+), 16 deletions(-) > >> > >> diff --git a/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c > >> b/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c index 8dba729..b240e05 > >> 100644 > >> --- a/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c > >> +++ b/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c > >> @@ -325,7 +325,7 @@ static void adv7511_set_link_config(struct adv7511 > >> *adv7511, adv7511->rgb = config->input_colorspace == HDMI_COLORSPACE_RGB; > >> > >> } > >> > >> -static void adv7511_power_on(struct adv7511 *adv7511) > >> +static void __adv7511_power_on(struct adv7511 *adv7511) > >> { > >> adv7511->current_edid_segment = -1; > >> > >> @@ -343,6 +343,7 @@ static void adv7511_power_on(struct adv7511 *adv7511) > >> ADV7511_INT1_DDC_ERROR); > >> } > >> > >> + > > > > This isn't needed. > > Apologies. I saw this right after I sent it! > > >> /* > >> * Per spec it is allowed to pulse the HPD signal to indicate that > >> the > >> * EDID information has changed. Some monitors do this when they > >> wakeup > >> @@ -362,11 +363,15 @@ static void adv7511_power_on(struct adv7511 > >> *adv7511) > >> > >> if (adv7511->type == ADV7533) > >> adv7533_dsi_power_on(adv7511); > >> +} > >> > >> +static void adv7511_power_on(struct adv7511 *adv7511) > >> +{ > >> + __adv7511_power_on(adv7511); > >> adv7511->powered = true; > >> } > >> > >> -static void adv7511_power_off(struct adv7511 *adv7511) > >> +static void __adv7511_power_off(struct adv7511 *adv7511) > >> { > >> /* TODO: setup additional power down modes */ > >> regmap_update_bits(adv7511->regmap, ADV7511_REG_POWER, > >> @@ -376,7 +381,11 @@ static void adv7511_power_off(struct adv7511 > >> *adv7511) > >> > >> if (adv7511->type == ADV7533) > >> adv7533_dsi_power_off(adv7511); > >> +} > >> > >> +static void adv7511_power_off(struct adv7511 *adv7511) > >> +{ > >> + __adv7511_power_off(adv7511); > >> adv7511->powered = false; > >> } > >> > >> @@ -545,24 +554,13 @@ static int adv7511_get_modes(struct adv7511 > >> *adv7511, > >> unsigned int count; > >> > >> /* Reading the EDID only works if the device is powered */ > >> - if (!adv7511->powered) { > >> - regmap_update_bits(adv7511->regmap, ADV7511_REG_POWER, > >> - ADV7511_POWER_POWER_DOWN, 0); > >> - if (adv7511->i2c_main->irq) { > >> - regmap_write(adv7511->regmap, > > > > ADV7511_REG_INT_ENABLE(0), > > > >> - ADV7511_INT0_EDID_READY); > >> - regmap_write(adv7511->regmap, > >> ADV7511_REG_INT_ENABLE(1), > >> - ADV7511_INT1_DDC_ERROR); > >> - } > >> - adv7511->current_edid_segment = -1; > >> - } > >> + if (!adv7511->powered) > >> + __adv7511_power_on(adv7511); > > > > The __adv7511_power_on() function does more than the above, in particular > > it performs an expensive regcache_sync() and calls adv7533_dsi_power_on() > > for the ADV7533. Don't those operations have side effects that are either > > not wanted or not needed here ? In any case this patch modifies the > > behaviour of the driver, which needs to be documented in the kernel > > message. > > Sorry, what do you mean by kernel message? Commit message, maybe? Sorry, yes, I meant commit message. > Fair point, I'll review the adv7533_dsi_power_on bits and see if they > should move out to the external function rather then the internal one. > Similarly for the regcache_sync. > > Thanks so much for the review! -- Regards, Laurent Pinchart