Linux-ARM-Kernel Archive on lore.kernel.org
 help / color / Atom feed
From: Lucas Stach <l.stach@pengutronix.de>
To: "Guido Günther" <agx@sigxcpu.org>,
	"Kishon Vijay Abraham I" <kishon@ti.com>,
	"Shawn Guo" <shawnguo@kernel.org>,
	"Sascha Hauer" <s.hauer@pengutronix.de>,
	"Pengutronix Kernel Team" <kernel@pengutronix.de>,
	"Fabio Estevam" <festevam@gmail.com>,
	"NXP Linux Team" <linux-imx@nxp.com>,
	"Robert Chiras" <robert.chiras@nxp.com>,
	"Sam Ravnborg" <sam@ravnborg.org>,
	linux-kernel@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v2 1/1] phy: fsl-imx8-mipi-dphy: Hook into runtime pm
Date: Wed, 16 Dec 2020 13:05:36 +0100
Message-ID: <ee22b072e0abe07559a3e6a63ccf6ece064a46cb.camel@pengutronix.de> (raw)
In-Reply-To: <eae82b09fd5ed39dbcd88cc10ce60338474183aa.1608118008.git.agx@sigxcpu.org>

Hi Guido,

this time hopefully with less broken quoting. My mailer is driving me
mad right now...

Am Mittwoch, dem 16.12.2020 um 12:27 +0100 schrieb Guido Günther:
> This allows us to shut down the mipi power domain on the imx8. The
> alternative would be to drop the dphy from the mipi power domain in the
> SOCs device tree and only have the DSI host controller visible there but
> since the PD is mostly about the PHY that would defeat it's purpose.

Adding RPM support is exactly the right course of action.

> This allows to shut off the power domain hen blanking the LCD panel:
> 
> pm_genpd_summary before:
> 
> domain                          status          slaves
>     /device                                             runtime status
> ----------------------------------------------------------------------
> mipi                            on
>     /devices/platform/soc@0/soc@0:bus@30800000/30a00300.dphy  unsupported
>     /devices/platform/soc@0/soc@0:bus@30800000/30a00000.mipi_dsi  suspended
> 
> after:
> 
> mipi                            off-0
>     /devices/platform/soc@0/soc@0:bus@30800000/30a00300.dphy  suspended
>     /devices/platform/soc@0/soc@0:bus@30800000/30a00000.mipi_dsi  suspended
> 
> Signed-off-by: Guido Günther <agx@sigxcpu.org>
> ---
>  .../phy/freescale/phy-fsl-imx8-mipi-dphy.c    | 22 ++++++++++++++++++-
>  1 file changed, 21 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/phy/freescale/phy-fsl-imx8-mipi-dphy.c b/drivers/phy/freescale/phy-fsl-imx8-mipi-dphy.c
> index a95572b397ca..34e2d801e520 100644
> --- a/drivers/phy/freescale/phy-fsl-imx8-mipi-dphy.c
> +++ b/drivers/phy/freescale/phy-fsl-imx8-mipi-dphy.c
> @@ -14,6 +14,7 @@
>  #include <linux/of_platform.h>
>  #include <linux/phy/phy.h>
>  #include <linux/platform_device.h>
> +#include <linux/pm_runtime.h>
>  #include <linux/regmap.h>
>  
>  /* DPHY registers */
> @@ -93,6 +94,7 @@ struct mixel_dphy_cfg {
>  };
>  
>  struct mixel_dphy_priv {
> +	struct device *dev;
>  	struct mixel_dphy_cfg cfg;
>  	struct regmap *regmap;
>  	struct clk *phy_ref_clk;
> @@ -382,6 +384,7 @@ static int mixel_dphy_power_on(struct phy *phy)
>  	ret = clk_prepare_enable(priv->phy_ref_clk);
>  	if (ret < 0)
>  		return ret;
> +	pm_runtime_get_sync(priv->dev);
>  

This call can fail and will leave you with an elevated rpm refcount.
Better use the new pm_runtime_resume_and_get to avoid this issue? 

Nitpick: I would add a blank line before the call.

Regards,
Lucas


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

  parent reply index

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-12-16 11:27 [PATCH v2 0/1] " Guido Günther
2020-12-16 11:27 ` [PATCH v2 1/1] " Guido Günther
2020-12-16 11:58   ` Lucas Stach
2020-12-16 12:05   ` Lucas Stach [this message]
2020-12-16 18:25     ` Guido Günther
2021-02-20  5:37   ` Liu Ying
2021-02-20  5:50     ` Liu Ying
2021-02-22 18:39     ` Guido Günther

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=ee22b072e0abe07559a3e6a63ccf6ece064a46cb.camel@pengutronix.de \
    --to=l.stach@pengutronix.de \
    --cc=agx@sigxcpu.org \
    --cc=festevam@gmail.com \
    --cc=kernel@pengutronix.de \
    --cc=kishon@ti.com \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-imx@nxp.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=robert.chiras@nxp.com \
    --cc=s.hauer@pengutronix.de \
    --cc=sam@ravnborg.org \
    --cc=shawnguo@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

Linux-ARM-Kernel Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-arm-kernel/0 linux-arm-kernel/git/0.git
	git clone --mirror https://lore.kernel.org/linux-arm-kernel/1 linux-arm-kernel/git/1.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-arm-kernel linux-arm-kernel/ https://lore.kernel.org/linux-arm-kernel \
		linux-arm-kernel@lists.infradead.org
	public-inbox-index linux-arm-kernel

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.infradead.lists.linux-arm-kernel


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git