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Message-ID: <91956712-0bdf-c932-5f8f-e7bb911f8d9f@ideasonboard.com>
Date:   Tue, 19 Sep 2023 10:09:20 +0300
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Subject: Re: [RFT PATCH 5/6] drm: Call drm_atomic_helper_shutdown() at
 shutdown/remove time for misc drivers
Content-Language: en-US
To:     Douglas Anderson <dianders@chromium.org>,
        dri-devel@lists.freedesktop.org, Maxime Ripard <mripard@kernel.org>
Cc:     airlied@gmail.com, airlied@redhat.com,
        alexandre.torgue@foss.st.com, andrew@aj.id.au, daniel@ffwll.ch,
        emma@anholt.net, hdegoede@redhat.com, jfalempe@redhat.com,
        joel@jms.id.au, jyri.sarha@iki.fi, linus.walleij@linaro.org,
        linux-arm-kernel@lists.infradead.org,
        linux-aspeed@lists.ozlabs.org, linux-kernel@vger.kernel.org,
        linux-stm32@st-md-mailman.stormreply.com,
        mcoquelin.stm32@gmail.com, philippe.cornu@foss.st.com,
        raphael.gallais-pou@foss.st.com, tzimmermann@suse.de,
        yannick.fertre@foss.st.com
References: <20230901234015.566018-1-dianders@chromium.org>
 <20230901163944.RFT.5.I771eb4bd03d8772b19e7dcfaef3e2c167bce5846@changeid>
From:   Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
In-Reply-To: <20230901163944.RFT.5.I771eb4bd03d8772b19e7dcfaef3e2c167bce5846@changeid>
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Precedence: bulk

On 02/09/2023 02:39, Douglas Anderson wrote:
> Based on grepping through the source code these drivers appear to be
> missing a call to drm_atomic_helper_shutdown() at system shutdown time
> and at driver remove (or unbind) time. Among other things, this means
> that if a panel is in use that it won't be cleanly powered off at
> system shutdown time.
> 
> The fact that we should call drm_atomic_helper_shutdown() in the case
> of OS shutdown/restart and at driver remove (or unbind) time comes
> straight out of the kernel doc "driver instance overview" in
> drm_drv.c.

Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>

and tested on Beagle Bone Black (tilcdc):

Tested-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com> # tilcdc

  Tomi

> 
> A few notes about these fixes:
> - I confirmed that these drivers were all DRIVER_MODESET type drivers,
>    which I believe makes this relevant.
> - I confirmed that these drivers were all DRIVER_ATOMIC.
> - When adding drm_atomic_helper_shutdown() to the remove/unbind path,
>    I added it after drm_kms_helper_poll_fini() when the driver had
>    it. This seemed to be what other drivers did. If
>    drm_kms_helper_poll_fini() wasn't there I added it straight after
>    drm_dev_unregister().
> - This patch deals with drivers using the component model in similar
>    ways as the patch ("drm: Call drm_atomic_helper_shutdown() at
>    shutdown time for misc drivers")
> - These fixes rely on the patch ("drm/atomic-helper:
>    drm_atomic_helper_shutdown(NULL) should be a noop") to simplify
>    shutdown.
> 
> Suggested-by: Maxime Ripard <mripard@kernel.org>
> Signed-off-by: Douglas Anderson <dianders@chromium.org>
> ---
> 
>   drivers/gpu/drm/aspeed/aspeed_gfx_drv.c |  7 +++++++
>   drivers/gpu/drm/mgag200/mgag200_drv.c   |  8 ++++++++
>   drivers/gpu/drm/pl111/pl111_drv.c       |  7 +++++++
>   drivers/gpu/drm/stm/drv.c               |  7 +++++++
>   drivers/gpu/drm/tilcdc/tilcdc_drv.c     | 11 ++++++++++-
>   drivers/gpu/drm/tve200/tve200_drv.c     |  7 +++++++
>   drivers/gpu/drm/vboxvideo/vbox_drv.c    | 10 ++++++++++
>   7 files changed, 56 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/aspeed/aspeed_gfx_drv.c b/drivers/gpu/drm/aspeed/aspeed_gfx_drv.c
> index d207b03f8357..78122b35a0cb 100644
> --- a/drivers/gpu/drm/aspeed/aspeed_gfx_drv.c
> +++ b/drivers/gpu/drm/aspeed/aspeed_gfx_drv.c
> @@ -358,11 +358,18 @@ static void aspeed_gfx_remove(struct platform_device *pdev)
>   	sysfs_remove_group(&pdev->dev.kobj, &aspeed_sysfs_attr_group);
>   	drm_dev_unregister(drm);
>   	aspeed_gfx_unload(drm);
> +	drm_atomic_helper_shutdown(drm);
> +}
> +
> +static void aspeed_gfx_shutdown(struct platform_device *pdev)
> +{
> +	drm_atomic_helper_shutdown(platform_get_drvdata(pdev));
>   }
>   
>   static struct platform_driver aspeed_gfx_platform_driver = {
>   	.probe		= aspeed_gfx_probe,
>   	.remove_new	= aspeed_gfx_remove,
> +	.shutdown	= aspeed_gfx_shutdown,
>   	.driver = {
>   		.name = "aspeed_gfx",
>   		.of_match_table = aspeed_gfx_match,
> diff --git a/drivers/gpu/drm/mgag200/mgag200_drv.c b/drivers/gpu/drm/mgag200/mgag200_drv.c
> index abddf37f0ea1..2fb18b782b05 100644
> --- a/drivers/gpu/drm/mgag200/mgag200_drv.c
> +++ b/drivers/gpu/drm/mgag200/mgag200_drv.c
> @@ -10,6 +10,7 @@
>   #include <linux/pci.h>
>   
>   #include <drm/drm_aperture.h>
> +#include <drm/drm_atomic_helper.h>
>   #include <drm/drm_drv.h>
>   #include <drm/drm_fbdev_generic.h>
>   #include <drm/drm_file.h>
> @@ -278,6 +279,12 @@ static void mgag200_pci_remove(struct pci_dev *pdev)
>   	struct drm_device *dev = pci_get_drvdata(pdev);
>   
>   	drm_dev_unregister(dev);
> +	drm_atomic_helper_shutdown(dev);
> +}
> +
> +static void mgag200_pci_shutdown(struct pci_dev *pdev)
> +{
> +	drm_atomic_helper_shutdown(pci_get_drvdata(pdev));
>   }
>   
>   static struct pci_driver mgag200_pci_driver = {
> @@ -285,6 +292,7 @@ static struct pci_driver mgag200_pci_driver = {
>   	.id_table = mgag200_pciidlist,
>   	.probe = mgag200_pci_probe,
>   	.remove = mgag200_pci_remove,
> +	.shutdown = mgag200_pci_shutdown,
>   };
>   
>   drm_module_pci_driver_if_modeset(mgag200_pci_driver, mgag200_modeset);
> diff --git a/drivers/gpu/drm/pl111/pl111_drv.c b/drivers/gpu/drm/pl111/pl111_drv.c
> index ba3b5b5f0cdf..02e6b74d5016 100644
> --- a/drivers/gpu/drm/pl111/pl111_drv.c
> +++ b/drivers/gpu/drm/pl111/pl111_drv.c
> @@ -323,12 +323,18 @@ static void pl111_amba_remove(struct amba_device *amba_dev)
>   	struct pl111_drm_dev_private *priv = drm->dev_private;
>   
>   	drm_dev_unregister(drm);
> +	drm_atomic_helper_shutdown(drm);
>   	if (priv->panel)
>   		drm_panel_bridge_remove(priv->bridge);
>   	drm_dev_put(drm);
>   	of_reserved_mem_device_release(dev);
>   }
>   
> +static void pl111_amba_shutdown(struct amba_device *amba_dev)
> +{
> +	drm_atomic_helper_shutdown(amba_get_drvdata(amba_dev));
> +}
> +
>   /*
>    * This early variant lacks the 565 and 444 pixel formats.
>    */
> @@ -431,6 +437,7 @@ static struct amba_driver pl111_amba_driver __maybe_unused = {
>   	},
>   	.probe = pl111_amba_probe,
>   	.remove = pl111_amba_remove,
> +	.shutdown = pl111_amba_shutdown,
>   	.id_table = pl111_id_table,
>   };
>   
> diff --git a/drivers/gpu/drm/stm/drv.c b/drivers/gpu/drm/stm/drv.c
> index c68c831136c9..e8523abef27a 100644
> --- a/drivers/gpu/drm/stm/drv.c
> +++ b/drivers/gpu/drm/stm/drv.c
> @@ -114,6 +114,7 @@ static void drv_unload(struct drm_device *ddev)
>   	DRM_DEBUG("%s\n", __func__);
>   
>   	drm_kms_helper_poll_fini(ddev);
> +	drm_atomic_helper_shutdown(ddev);
>   	ltdc_unload(ddev);
>   }
>   
> @@ -225,6 +226,11 @@ static void stm_drm_platform_remove(struct platform_device *pdev)
>   	drm_dev_put(ddev);
>   }
>   
> +static void stm_drm_platform_shutdown(struct platform_device *pdev)
> +{
> +	drm_atomic_helper_shutdown(platform_get_drvdata(pdev));
> +}
> +
>   static const struct of_device_id drv_dt_ids[] = {
>   	{ .compatible = "st,stm32-ltdc"},
>   	{ /* end node */ },
> @@ -234,6 +240,7 @@ MODULE_DEVICE_TABLE(of, drv_dt_ids);
>   static struct platform_driver stm_drm_platform_driver = {
>   	.probe = stm_drm_platform_probe,
>   	.remove_new = stm_drm_platform_remove,
> +	.shutdown = stm_drm_platform_shutdown,
>   	.driver = {
>   		.name = "stm32-display",
>   		.of_match_table = drv_dt_ids,
> diff --git a/drivers/gpu/drm/tilcdc/tilcdc_drv.c b/drivers/gpu/drm/tilcdc/tilcdc_drv.c
> index fe56beea3e93..8ebd7134ee21 100644
> --- a/drivers/gpu/drm/tilcdc/tilcdc_drv.c
> +++ b/drivers/gpu/drm/tilcdc/tilcdc_drv.c
> @@ -175,6 +175,7 @@ static void tilcdc_fini(struct drm_device *dev)
>   		drm_dev_unregister(dev);
>   
>   	drm_kms_helper_poll_fini(dev);
> +	drm_atomic_helper_shutdown(dev);
>   	tilcdc_irq_uninstall(dev);
>   	drm_mode_config_cleanup(dev);
>   
> @@ -389,6 +390,7 @@ static int tilcdc_init(const struct drm_driver *ddrv, struct device *dev)
>   
>   init_failed:
>   	tilcdc_fini(ddev);
> +	platform_set_drvdata(pdev, NULL);
>   
>   	return ret;
>   }
> @@ -537,7 +539,8 @@ static void tilcdc_unbind(struct device *dev)
>   	if (!ddev->dev_private)
>   		return;
>   
> -	tilcdc_fini(dev_get_drvdata(dev));
> +	tilcdc_fini(ddev);
> +	dev_set_drvdata(dev, NULL);
>   }
>   
>   static const struct component_master_ops tilcdc_comp_ops = {
> @@ -582,6 +585,11 @@ static int tilcdc_pdev_remove(struct platform_device *pdev)
>   	return 0;
>   }
>   
> +static void tilcdc_pdev_shutdown(struct platform_device *pdev)
> +{
> +	drm_atomic_helper_shutdown(platform_get_drvdata(pdev));
> +}
> +
>   static const struct of_device_id tilcdc_of_match[] = {
>   		{ .compatible = "ti,am33xx-tilcdc", },
>   		{ .compatible = "ti,da850-tilcdc", },
> @@ -592,6 +600,7 @@ MODULE_DEVICE_TABLE(of, tilcdc_of_match);
>   static struct platform_driver tilcdc_platform_driver = {
>   	.probe      = tilcdc_pdev_probe,
>   	.remove     = tilcdc_pdev_remove,
> +	.shutdown   = tilcdc_pdev_shutdown,
>   	.driver     = {
>   		.name   = "tilcdc",
>   		.pm     = pm_sleep_ptr(&tilcdc_pm_ops),
> diff --git a/drivers/gpu/drm/tve200/tve200_drv.c b/drivers/gpu/drm/tve200/tve200_drv.c
> index 0bb56d063536..acce210e2554 100644
> --- a/drivers/gpu/drm/tve200/tve200_drv.c
> +++ b/drivers/gpu/drm/tve200/tve200_drv.c
> @@ -242,6 +242,7 @@ static void tve200_remove(struct platform_device *pdev)
>   	struct tve200_drm_dev_private *priv = drm->dev_private;
>   
>   	drm_dev_unregister(drm);
> +	drm_atomic_helper_shutdown(drm);
>   	if (priv->panel)
>   		drm_panel_bridge_remove(priv->bridge);
>   	drm_mode_config_cleanup(drm);
> @@ -249,6 +250,11 @@ static void tve200_remove(struct platform_device *pdev)
>   	drm_dev_put(drm);
>   }
>   
> +static void tve200_shutdown(struct platform_device *pdev)
> +{
> +	drm_atomic_helper_shutdown(platform_get_drvdata(pdev));
> +}
> +
>   static const struct of_device_id tve200_of_match[] = {
>   	{
>   		.compatible = "faraday,tve200",
> @@ -263,6 +269,7 @@ static struct platform_driver tve200_driver = {
>   	},
>   	.probe = tve200_probe,
>   	.remove_new = tve200_remove,
> +	.shutdown = tve200_shutdown,
>   };
>   drm_module_platform_driver(tve200_driver);
>   
> diff --git a/drivers/gpu/drm/vboxvideo/vbox_drv.c b/drivers/gpu/drm/vboxvideo/vbox_drv.c
> index 4fee15c97c34..047b95812334 100644
> --- a/drivers/gpu/drm/vboxvideo/vbox_drv.c
> +++ b/drivers/gpu/drm/vboxvideo/vbox_drv.c
> @@ -12,6 +12,7 @@
>   #include <linux/vt_kern.h>
>   
>   #include <drm/drm_aperture.h>
> +#include <drm/drm_atomic_helper.h>
>   #include <drm/drm_drv.h>
>   #include <drm/drm_fbdev_generic.h>
>   #include <drm/drm_file.h>
> @@ -97,11 +98,19 @@ static void vbox_pci_remove(struct pci_dev *pdev)
>   	struct vbox_private *vbox = pci_get_drvdata(pdev);
>   
>   	drm_dev_unregister(&vbox->ddev);
> +	drm_atomic_helper_shutdown(&vbox->ddev);
>   	vbox_irq_fini(vbox);
>   	vbox_mode_fini(vbox);
>   	vbox_hw_fini(vbox);
>   }
>   
> +static void vbox_pci_shutdown(struct pci_dev *pdev)
> +{
> +	struct vbox_private *vbox = pci_get_drvdata(pdev);
> +
> +	drm_atomic_helper_shutdown(&vbox->ddev);
> +}
> +
>   static int vbox_pm_suspend(struct device *dev)
>   {
>   	struct vbox_private *vbox = dev_get_drvdata(dev);
> @@ -165,6 +174,7 @@ static struct pci_driver vbox_pci_driver = {
>   	.id_table = pciidlist,
>   	.probe = vbox_pci_probe,
>   	.remove = vbox_pci_remove,
> +	.shutdown = vbox_pci_shutdown,
>   	.driver.pm = pm_sleep_ptr(&vbox_pm_ops),
>   };
>