From: Maxime Ripard <maxime@cerno.tech>
To: Guillaume Ranquet <granquet@baylibre.com>
Cc: airlied@linux.ie, angelogioacchino.delregno@collabora.com,
chunfeng.yun@mediatek.com, chunkuang.hu@kernel.org,
ck.hu@mediatek.com, daniel@ffwll.ch, deller@gmx.de,
jitao.shi@mediatek.com, kishon@ti.com, krzk+dt@kernel.org,
maarten.lankhorst@linux.intel.com, matthias.bgg@gmail.com,
p.zabel@pengutronix.de, robh+dt@kernel.org, tzimmermann@suse.de,
vkoul@kernel.org, devicetree@vger.kernel.org,
dri-devel@lists.freedesktop.org,
linux-arm-kernel@lists.infradead.org,
linux-fbdev@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-mediatek@lists.infradead.org,
linux-phy@lists.infradead.org, markyacoub@google.com,
Markus Schneider-Pargmann <msp@baylibre.com>,
kernel test robot <lkp@intel.com>
Subject: Re: [PATCH v9 18/22] drm/mediatek: Add mt8195 Embedded DisplayPort driver
Date: Wed, 25 May 2022 11:44:34 +0200 [thread overview]
Message-ID: <20220525094434.7qhycnobrmgiihuf@houat> (raw)
In-Reply-To: <CABnWg9tHRc_7VZ1z6NeMEDfQvxam_xOimBnM=hzBUqkhzPOSCA@mail.gmail.com>
[-- Attachment #1.1: Type: text/plain, Size: 4399 bytes --]
On Thu, May 19, 2022 at 09:26:59AM -0700, Guillaume Ranquet wrote:
> On Thu, 12 May 2022 09:44, Maxime Ripard <maxime@cerno.tech> wrote:
> >Hi,
> >
> >On Wed, May 11, 2022 at 05:59:13AM -0700, Guillaume Ranquet wrote:
> >> >> +#include <drm/drm_atomic_helper.h>
> >> >> +#include <drm/drm_bridge.h>
> >> >> +#include <drm/drm_crtc.h>
> >> >> +#include <drm/dp/drm_dp_helper.h>
> >> >> +#include <drm/drm_edid.h>
> >> >> +#include <drm/drm_of.h>
> >> >> +#include <drm/drm_panel.h>
> >> >> +#include <drm/drm_print.h>
> >> >> +#include <drm/drm_probe_helper.h>
> >> >> +#include <linux/arm-smccc.h>
> >> >> +#include <linux/clk.h>
> >> >> +#include <linux/delay.h>
> >> >> +#include <linux/errno.h>
> >> >> +#include <linux/kernel.h>
> >> >> +#include <linux/mfd/syscon.h>
> >> >> +#include <linux/nvmem-consumer.h>
> >> >> +#include <linux/of.h>
> >> >> +#include <linux/of_irq.h>
> >> >> +#include <linux/of_platform.h>
> >> >> +#include <linux/phy/phy.h>
> >> >> +#include <linux/platform_device.h>
> >> >> +#include <linux/pm_runtime.h>
> >> >> +#include <linux/regmap.h>
> >> >> +#include <sound/hdmi-codec.h>
> >> >> +#include <video/videomode.h>
> >> >> +
> >> >> +#include "mtk_dp_reg.h"
> >> >> +
> >> >> +#define MTK_DP_AUX_WAIT_REPLY_COUNT 20
> >> >> +#define MTK_DP_CHECK_SINK_CAP_TIMEOUT_COUNT 3
> >> >> +
> >> >> +//TODO: platform/device data or dts?
> >> >
> >> >DTS :)
> >>
> >> It's probably going to be a platform_data struct for v10...
> >> If I have time, I'll change it to a dts property for v10.
> >
> >I can't really imagine a case where we would need platform_data
> >nowadays. If you have a device tree, then it should be part of the
> >binding.
> >
> >What issue would you like to address by using a platform_data?
> >
>
> Ok, I'll migrate to dt then. I didn't realize platform_data were depreciated.
>
> Angelo wants the MAX_LINRATE and MAX_LANES defines to be configurable.
> I imagined platform_data would be more appropriate as (per my understanding) the
> limitation is associated with a specific SoC.
The entire device tree is nothing but a collection of data associated to
a specific SoC though :)
> >> >> +static struct edid *mtk_dp_get_edid(struct drm_bridge *bridge,
> >> >> + struct drm_connector *connector)
> >> >> +{
> >> >> + struct mtk_dp *mtk_dp = mtk_dp_from_bridge(bridge);
> >> >> + bool enabled = mtk_dp->enabled;
> >> >> + struct edid *new_edid = NULL;
> >> >> +
> >> >> + if (!enabled)
> >> >> + drm_bridge_chain_pre_enable(bridge);
> >> >> +
> >> >> + drm_dp_dpcd_writeb(&mtk_dp->aux, DP_SET_POWER, DP_SET_POWER_D0);
> >> >> + usleep_range(2000, 5000);
> >> >> +
> >> >> + if (mtk_dp_plug_state(mtk_dp))
> >> >> + new_edid = drm_get_edid(connector, &mtk_dp->aux.ddc);
> >> >> +
> >> >> + if (!enabled)
> >> >> + drm_bridge_chain_post_disable(bridge);
> >> >
> >> >Are you sure we can't get a mode set while get_edid is called?
> >> >
> >> >If we can, then you could end up disabling the device while it's being
> >> >powered on.
> >>
> >> I'm a bit unsure, I need to spend more time in the drm stack to make sure.
> >> I'll get back to you when I have a definitive answer.
> >
> >So, it looks like it's ok.
> >
> >get_edid is your implementation of get_modes, which is called by
> >drm_helper_probe_single_connector_modes
> >
> >https://elixir.bootlin.com/linux/latest/source/drivers/gpu/drm/drm_probe_helper.c#L416
> >
> >This is the standard implemantion of fill_modes, which is called
> >whenever the get_connector ioctl is called (or similar paths, like
> >drm_client_modeset_probe)
> >
> >drm_helper_probe_single_connector_modes is under the assumption that the
> >mode_config.mutex is held though, and that the big lock. So it should be
> >serialized there.
> >
> >Just for future proofing though, it would be better to use refcounting
> >there. Would runtime_pm work for you there?
> >
>
> Thx for looking into this for me.
> Not sure runtime_pm works here as it would only refcount if compiled
> with CONFIG_PM?
It should be enabled in most configurations these days, and you can
always depend on it in your Kconfig option.
> I'd rather use the enabled field as a refcounter instead of a boolean.
It's a bit more ad-hoc, but that would work too. Make sure to use a lock
or atomic operations though
Maxime
[-- Attachment #1.2: signature.asc --]
[-- Type: application/pgp-signature, Size: 228 bytes --]
[-- Attachment #2: Type: text/plain, Size: 170 bytes --]
_______________________________________________
Linux-mediatek mailing list
Linux-mediatek@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-mediatek
next prev parent reply other threads:[~2022-05-25 9:45 UTC|newest]
Thread overview: 67+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-03-27 22:39 [PATCH 00/22] drm/mediatek: Add mt8195 DisplayPort driver Guillaume Ranquet
2022-03-27 22:39 ` [PATCH v9 01/22] dt-bindings: mediatek,dpi: Add DP_INTF compatible Guillaume Ranquet
2022-03-29 10:42 ` Matthias Brugger
2022-03-30 5:11 ` [PATCH v9 01/22] dt-bindings: mediatek, dpi: " Miles Chen
2022-04-22 10:57 ` [PATCH v9 01/22] dt-bindings: mediatek,dpi: " Maxime Ripard
2022-05-11 12:37 ` [PATCH v9 01/22] dt-bindings: mediatek, dpi: " Guillaume Ranquet
2022-03-27 22:39 ` [PATCH v9 02/22] dt-bindings: mediatek,dp: Add Display Port binding Guillaume Ranquet
2022-03-28 12:51 ` [PATCH v9 02/22] dt-bindings: mediatek, dp: " Rob Herring
2022-03-28 16:33 ` [PATCH v9 02/22] dt-bindings: mediatek,dp: " Rob Herring
2022-03-30 5:12 ` [PATCH v9 02/22] dt-bindings: mediatek, dp: " Miles Chen
2022-03-27 22:39 ` [PATCH v9 03/22] dt-bindings: mediatek, dp_phy: Add Display Port PHY binding Guillaume Ranquet
2022-03-29 22:58 ` [PATCH v9 03/22] dt-bindings: mediatek,dp_phy: " Rob Herring
2022-04-12 10:06 ` Guillaume Ranquet
2022-03-30 5:12 ` [PATCH v9 03/22] dt-bindings: mediatek, dp_phy: " Miles Chen
2022-03-27 22:39 ` [PATCH v9 04/22] drm/edid: Convert cea_sad helper struct to kernelDoc Guillaume Ranquet
2022-03-28 8:04 ` AngeloGioacchino Del Regno
2022-04-12 8:57 ` Guillaume Ranquet
2022-03-27 22:39 ` [PATCH v9 05/22] drm/edid: Add cea_sad helpers for freq/length Guillaume Ranquet
2022-03-27 22:39 ` [PATCH v9 06/22] video/hdmi: Add audio_infoframe packing for DP Guillaume Ranquet
2022-03-28 8:09 ` AngeloGioacchino Del Regno
2022-04-12 8:59 ` Guillaume Ranquet
2022-03-27 22:39 ` [PATCH v9 07/22] drm/mediatek: dpi: move dpi limits to SoC config Guillaume Ranquet
2022-03-28 7:18 ` Rex-BC Chen
2022-03-27 22:39 ` [PATCH v9 08/22] drm/mediatek: dpi: implement a CK/DE pol toggle in " Guillaume Ranquet
2022-03-28 7:31 ` Rex-BC Chen
2022-03-27 22:39 ` [PATCH v9 09/22] drm/mediatek: dpi: implement a swap_input " Guillaume Ranquet
2022-03-28 8:33 ` Rex-BC Chen
2022-03-27 22:39 ` [PATCH v9 10/22] drm/mediatek: dpi: move dimension mask to " Guillaume Ranquet
2022-03-28 8:33 ` Rex-BC Chen
2022-03-27 22:39 ` [PATCH v9 11/22] drm/mediatek: dpi: move hvsize_mask " Guillaume Ranquet
2022-03-28 8:34 ` Rex-BC Chen
2022-03-27 22:39 ` [PATCH v9 12/22] drm/mediatek: dpi: move swap_shift " Guillaume Ranquet
2022-03-28 8:20 ` AngeloGioacchino Del Regno
2022-03-28 8:34 ` Rex-BC Chen
2022-03-27 22:39 ` [PATCH v9 13/22] drm/mediatek: dpi: move the yuv422_en_bit " Guillaume Ranquet
2022-03-28 8:54 ` Rex-BC Chen
2022-03-27 22:39 ` [PATCH v9 14/22] drm/mediatek: dpi: move the csc_enable bit " Guillaume Ranquet
2022-03-28 8:35 ` Rex-BC Chen
2022-03-27 22:39 ` [PATCH v9 15/22] drm/mediatek: dpi: Add dpintf support Guillaume Ranquet
2022-03-28 8:38 ` Rex-BC Chen
2022-04-12 9:10 ` Guillaume Ranquet
2022-03-29 3:16 ` Rex-BC Chen
2022-04-12 9:12 ` Guillaume Ranquet
2022-03-27 22:39 ` [PATCH v9 16/22] drm/meditek: dpi: Add matrix_sel helper Guillaume Ranquet
2022-03-28 8:49 ` Rex-BC Chen
2022-04-12 9:37 ` Guillaume Ranquet
2022-03-27 22:39 ` [PATCH v9 17/22] phy: phy-mtk-dp: Add driver for DP phy Guillaume Ranquet
2022-03-28 8:20 ` AngeloGioacchino Del Regno
2022-04-12 9:04 ` Guillaume Ranquet
2022-03-27 22:39 ` [PATCH v9 18/22] drm/mediatek: Add mt8195 Embedded DisplayPort driver Guillaume Ranquet
2022-03-28 9:14 ` AngeloGioacchino Del Regno
2022-04-12 9:46 ` Guillaume Ranquet
2022-04-13 7:50 ` AngeloGioacchino Del Regno
2022-03-29 3:34 ` Rex-BC Chen
2022-04-12 9:48 ` Guillaume Ranquet
2022-03-29 5:41 ` Rex-BC Chen
2022-04-12 10:03 ` Guillaume Ranquet
2022-04-29 8:39 ` Maxime Ripard
2022-05-11 12:59 ` Guillaume Ranquet
2022-05-12 7:44 ` Maxime Ripard
2022-05-19 16:26 ` Guillaume Ranquet
2022-05-25 9:44 ` Maxime Ripard [this message]
2022-03-27 22:39 ` [PATCH v9 19/22] drm/mediatek: Add mt8195 External DisplayPort support Guillaume Ranquet
2022-03-27 22:39 ` [PATCH v9 20/22] drm/mediatek: add hpd debounce Guillaume Ranquet
2022-03-27 22:39 ` [PATCH v9 21/22] drm/mediatek: change the aux retries times when receiving AUX_DEFER Guillaume Ranquet
2022-03-28 1:46 ` Rex-BC Chen
2022-03-27 22:39 ` [PATCH v9 22/22] drm/mediatek: DP audio support for mt8195 Guillaume Ranquet
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20220525094434.7qhycnobrmgiihuf@houat \
--to=maxime@cerno.tech \
--cc=airlied@linux.ie \
--cc=angelogioacchino.delregno@collabora.com \
--cc=chunfeng.yun@mediatek.com \
--cc=chunkuang.hu@kernel.org \
--cc=ck.hu@mediatek.com \
--cc=daniel@ffwll.ch \
--cc=deller@gmx.de \
--cc=devicetree@vger.kernel.org \
--cc=dri-devel@lists.freedesktop.org \
--cc=granquet@baylibre.com \
--cc=jitao.shi@mediatek.com \
--cc=kishon@ti.com \
--cc=krzk+dt@kernel.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-fbdev@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mediatek@lists.infradead.org \
--cc=linux-phy@lists.infradead.org \
--cc=lkp@intel.com \
--cc=maarten.lankhorst@linux.intel.com \
--cc=markyacoub@google.com \
--cc=matthias.bgg@gmail.com \
--cc=msp@baylibre.com \
--cc=p.zabel@pengutronix.de \
--cc=robh+dt@kernel.org \
--cc=tzimmermann@suse.de \
--cc=vkoul@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).