From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
To: dri-devel@lists.freedesktop.org
Cc: John Stultz <john.stultz@linaro.org>,
lkml <linux-kernel@vger.kernel.org>,
Wolfram Sang <wsa+renesas@sang-engineering.com>
Subject: Re: [PATCH 5/5 v3] drm/bridge: adv7511: Reuse __adv7511_power_on/off() when probing EDID
Date: Mon, 16 Jan 2017 18:03:11 +0200 [thread overview]
Message-ID: <1965576.h4kdXt2VDW@avalon> (raw)
In-Reply-To: <1483472502-16403-6-git-send-email-john.stultz@linaro.org>
Hi John,
Thank you for the patch.
On Tuesday 03 Jan 2017 11:41:42 John Stultz wrote:
> I've found that by just turning the chip on and off via the
> POWER_DOWN register, I end up getting i2c_transfer errors
> on HiKey.
>
> Investigating further, it seems some of the register state
> in the regmap cache is somehow getting lost. Using the logic
> in __adv7511_power_on/off() which syncs and dirtys the cache
> avoids this issue.
>
> Thus this patch changes the EDID probing logic so that we
> re-use the __adv7511_power_on/off() calls.
regcache_sync() is quite costly as it will write a bunch of registers.
Wouldn't it be more efficient to only write the registers that are needed for
EDID access ?
> Cc: David Airlie <airlied@linux.ie>
> Cc: Archit Taneja <architt@codeaurora.org>
> Cc: Wolfram Sang <wsa+renesas@sang-engineering.com>
> Cc: Lars-Peter Clausen <lars@metafoo.de>
> Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> Cc: dri-devel@lists.freedesktop.org
> Signed-off-by: John Stultz <john.stultz@linaro.org>
> ---
> drivers/gpu/drm/bridge/adv7511/adv7511_drv.c | 17 +++--------------
> 1 file changed, 3 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c
> b/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c index dbdb71c..24573e0
> 100644
> --- a/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c
> +++ b/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c
> @@ -572,24 +572,13 @@ 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);
>
> edid = drm_do_get_edid(connector, adv7511_get_edid_block, adv7511);
>
> if (!adv7511->powered)
> - regmap_update_bits(adv7511->regmap, ADV7511_REG_POWER,
> - ADV7511_POWER_POWER_DOWN,
> - ADV7511_POWER_POWER_DOWN);
> + __adv7511_power_off(adv7511);
>
> kfree(adv7511->edid);
> adv7511->edid = edid;
--
Regards,
Laurent Pinchart
next prev parent reply other threads:[~2017-01-16 16:02 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-01-03 19:41 [PATCH 0/5 v3] adv7511 EDID probing improvements John Stultz
2017-01-03 19:41 ` [PATCH 1/5 v3] drm/bridge: adv7511: Use work_struct to defer hotplug handing to out of irq context John Stultz
2017-01-03 19:41 ` [PATCH 2/5 v3] drm/bridge: adv7511: Switch to using drm_kms_helper_hotplug_event() John Stultz
2017-01-16 15:47 ` Laurent Pinchart
2017-01-16 15:56 ` Laurent Pinchart
2017-01-16 19:31 ` John Stultz
2017-01-03 19:41 ` [PATCH 3/5 v3] drm/bridge: adv7511: Enable HPD interrupts to support hotplug and improve monitor detection John Stultz
2017-01-03 19:41 ` [PATCH 4/5 v3] drm/bridge: adv7511: Rework adv7511_power_on/off() so they can be reused internally John Stultz
2017-01-16 15:50 ` Laurent Pinchart
2017-01-03 19:41 ` [PATCH 5/5 v3] drm/bridge: adv7511: Reuse __adv7511_power_on/off() when probing EDID John Stultz
2017-01-16 16:03 ` Laurent Pinchart [this message]
2017-01-16 20:14 ` John Stultz
2017-01-16 22:25 ` Laurent Pinchart
2017-01-16 23:16 ` [RFC][PATCH] drm/bridge: adv7511: Re-write the i2c address as it may have been lost John Stultz
2017-01-16 23:36 ` Laurent Pinchart
2017-01-16 23:39 ` John Stultz
2017-01-11 8:48 ` [PATCH 0/5 v3] adv7511 EDID probing improvements Archit Taneja
2017-01-12 0:06 ` John Stultz
2017-01-12 4:22 ` Archit Taneja
2017-01-16 15:57 ` Laurent Pinchart
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