Re: [PATCH] drm/komeda: Adds power management support

From: Sean Paul
Date: Tue Oct 08 2019 - 14:13:57 EST


On Tue, Oct 8, 2019 at 1:47 PM Sean Paul <sean@xxxxxxxxxx> wrote:
>
> On Mon, Sep 23, 2019 at 01:59:25AM +0000, Lowry Li (Arm Technology China) wrote:
> > From: "Lowry Li (Arm Technology China)" <Lowry.Li@xxxxxxx>
> >
> > Adds system power management support in KMS kernel driver.
> >
> > Depends on:
> > https://patchwork.freedesktop.org/series/62377/
> >
> > Changes since v1:
> > Since we have unified mclk/pclk/pipeline->aclk to one mclk, which will
> > be turned on/off when crtc atomic enable/disable, removed runtime power
> > management.
> > Removes run time get/put related flow.
> > Adds to disable the aclk when register access finished.
> >
> > Changes since v2:
> > Rebases to the drm-misc-next branch.
> >
> > Signed-off-by: Lowry Li (Arm Technology China) <lowry.li@xxxxxxx>
> > ---
> > .../gpu/drm/arm/display/komeda/komeda_crtc.c | 1 -
> > .../gpu/drm/arm/display/komeda/komeda_dev.c | 65 +++++++++++++++++--
> > .../gpu/drm/arm/display/komeda/komeda_dev.h | 3 +
> > .../gpu/drm/arm/display/komeda/komeda_drv.c | 30 ++++++++-
> > 4 files changed, 91 insertions(+), 8 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c b/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c
> > index 38d5cb20e908..b47c0dabd0d1 100644
> > --- a/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c
> > +++ b/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c
> > @@ -5,7 +5,6 @@
> > *
> > */
> > #include <linux/clk.h>
> > -#include <linux/pm_runtime.h>
> > #include <linux/spinlock.h>
> >
> > #include <drm/drm_atomic.h>
> > diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_dev.c b/drivers/gpu/drm/arm/display/komeda/komeda_dev.c
> > index bee4633cdd9f..8a03324f02a5 100644
> > --- a/drivers/gpu/drm/arm/display/komeda/komeda_dev.c
> > +++ b/drivers/gpu/drm/arm/display/komeda/komeda_dev.c
> > @@ -258,7 +258,7 @@ struct komeda_dev *komeda_dev_create(struct device *dev)
> > product->product_id,
> > MALIDP_CORE_ID_PRODUCT_ID(mdev->chip.core_id));
> > err = -ENODEV;
> > - goto err_cleanup;
> > + goto disable_clk;
> > }
> >
> > DRM_INFO("Found ARM Mali-D%x version r%dp%d\n",
> > @@ -271,19 +271,19 @@ struct komeda_dev *komeda_dev_create(struct device *dev)
> > err = mdev->funcs->enum_resources(mdev);
> > if (err) {
> > DRM_ERROR("enumerate display resource failed.\n");
> > - goto err_cleanup;
> > + goto disable_clk;
> > }
> >
> > err = komeda_parse_dt(dev, mdev);
> > if (err) {
> > DRM_ERROR("parse device tree failed.\n");
> > - goto err_cleanup;
> > + goto disable_clk;
> > }
> >
> > err = komeda_assemble_pipelines(mdev);
> > if (err) {
> > DRM_ERROR("assemble display pipelines failed.\n");
> > - goto err_cleanup;
> > + goto disable_clk;
> > }
> >
> > dev->dma_parms = &mdev->dma_parms;
> > @@ -296,11 +296,14 @@ struct komeda_dev *komeda_dev_create(struct device *dev)
> > if (mdev->iommu && mdev->funcs->connect_iommu) {
> > err = mdev->funcs->connect_iommu(mdev);
> > if (err) {
> > + DRM_ERROR("connect iommu failed.\n");
> > mdev->iommu = NULL;
> > - goto err_cleanup;
> > + goto disable_clk;
> > }
> > }
> >
> > + clk_disable_unprepare(mdev->aclk);
> > +
> > err = sysfs_create_group(&dev->kobj, &komeda_sysfs_attr_group);
> > if (err) {
> > DRM_ERROR("create sysfs group failed.\n");
> > @@ -313,6 +316,8 @@ struct komeda_dev *komeda_dev_create(struct device *dev)
> >
> > return mdev;
> >
> > +disable_clk:
> > + clk_disable_unprepare(mdev->aclk);
> > err_cleanup:
> > komeda_dev_destroy(mdev);
> > return ERR_PTR(err);
> > @@ -330,8 +335,12 @@ void komeda_dev_destroy(struct komeda_dev *mdev)
> > debugfs_remove_recursive(mdev->debugfs_root);
> > #endif
> >
> > + if (mdev->aclk)
> > + clk_prepare_enable(mdev->aclk);
> > +
> > if (mdev->iommu && mdev->funcs->disconnect_iommu)
> > - mdev->funcs->disconnect_iommu(mdev);
> > + if (mdev->funcs->disconnect_iommu(mdev))
> > + DRM_ERROR("disconnect iommu failed.\n");
> > mdev->iommu = NULL;
> >
> > for (i = 0; i < mdev->n_pipelines; i++) {
> > @@ -359,3 +368,47 @@ void komeda_dev_destroy(struct komeda_dev *mdev)
> >
> > devm_kfree(dev, mdev);
> > }
> > +
> > +int komeda_dev_resume(struct komeda_dev *mdev)
> > +{
> > + int ret = 0;
> > +
> > + clk_prepare_enable(mdev->aclk);
> > +
> > + if (mdev->iommu && mdev->funcs->connect_iommu) {
> > + ret = mdev->funcs->connect_iommu(mdev);
> > + if (ret < 0) {
> > + DRM_ERROR("connect iommu failed.\n");
> > + goto disable_clk;
> > + }
> > + }
> > +
> > + ret = mdev->funcs->enable_irq(mdev);
> > +
> > +disable_clk:
> > + clk_disable_unprepare(mdev->aclk);
> > +
> > + return ret;
> > +}
> > +
> > +int komeda_dev_suspend(struct komeda_dev *mdev)
> > +{
> > + int ret = 0;
> > +
> > + clk_prepare_enable(mdev->aclk);
> > +
> > + if (mdev->iommu && mdev->funcs->disconnect_iommu) {
> > + ret = mdev->funcs->disconnect_iommu(mdev);
> > + if (ret < 0) {
> > + DRM_ERROR("disconnect iommu failed.\n");
> > + goto disable_clk;
> > + }
> > + }
> > +
> > + ret = mdev->funcs->disable_irq(mdev);
> > +
> > +disable_clk:
> > + clk_disable_unprepare(mdev->aclk);
> > +
> > + return ret;
> > +}
> > diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_dev.h b/drivers/gpu/drm/arm/display/komeda/komeda_dev.h
> > index 8acf8c0601cc..414200233b64 100644
> > --- a/drivers/gpu/drm/arm/display/komeda/komeda_dev.h
> > +++ b/drivers/gpu/drm/arm/display/komeda/komeda_dev.h
> > @@ -224,4 +224,7 @@ void komeda_print_events(struct komeda_events *evts);
> > static inline void komeda_print_events(struct komeda_events *evts) {}
> > #endif
> >
> > +int komeda_dev_resume(struct komeda_dev *mdev);
> > +int komeda_dev_suspend(struct komeda_dev *mdev);
> > +
> > #endif /*_KOMEDA_DEV_H_*/
> > diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_drv.c b/drivers/gpu/drm/arm/display/komeda/komeda_drv.c
> > index 69ace6f9055d..d6c2222c5d33 100644
> > --- a/drivers/gpu/drm/arm/display/komeda/komeda_drv.c
> > +++ b/drivers/gpu/drm/arm/display/komeda/komeda_drv.c
> > @@ -8,6 +8,7 @@
> > #include <linux/kernel.h>
> > #include <linux/platform_device.h>
> > #include <linux/component.h>
> > +#include <linux/pm_runtime.h>
> > #include <drm/drm_of.h>
> > #include "komeda_dev.h"
> > #include "komeda_kms.h"
> > @@ -136,13 +137,40 @@ static const struct of_device_id komeda_of_match[] = {
> >
> > MODULE_DEVICE_TABLE(of, komeda_of_match);
> >
> > +static int __maybe_unused komeda_pm_suspend(struct device *dev)
> > +{
> > + struct komeda_drv *mdrv = dev_get_drvdata(dev);
> > + struct drm_device *drm = &mdrv->kms->base;
> > + int res;
> > +
> > + res = drm_mode_config_helper_suspend(drm);
>
> Just noticed this while prepping the -misc pull request.
>
> You should use the atomic helpers instead, drm_atomic_helper_suspend and
> drm_atomic_helper_resume.
>

Hmm, looks like I was mistaken. For some reason, I thought this was
legacy but looking into mode_config_helper_suspend(), that will gets
you kms_helper_poll_disable/enable as well as stashes the state in
mode_config. So less work is better :)

Sean

> > +
> > + komeda_dev_suspend(mdrv->mdev);
> > +
> > + return res;
> > +}
> > +
> > +static int __maybe_unused komeda_pm_resume(struct device *dev)
> > +{
> > + struct komeda_drv *mdrv = dev_get_drvdata(dev);
> > + struct drm_device *drm = &mdrv->kms->base;
> > +
> > + komeda_dev_resume(mdrv->mdev);
> > +
> > + return drm_mode_config_helper_resume(drm);
> > +}
> > +
> > +static const struct dev_pm_ops komeda_pm_ops = {
> > + SET_SYSTEM_SLEEP_PM_OPS(komeda_pm_suspend, komeda_pm_resume)
> > +};
> > +
> > static struct platform_driver komeda_platform_driver = {
> > .probe = komeda_platform_probe,
> > .remove = komeda_platform_remove,
> > .driver = {
> > .name = "komeda",
> > .of_match_table = komeda_of_match,
> > - .pm = NULL,
> > + .pm = &komeda_pm_ops,
> > },
> > };
> >
> > --
> > 2.17.1
> >
> > _______________________________________________
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> > dri-devel@xxxxxxxxxxxxxxxxxxxxx
> > https://lists.freedesktop.org/mailman/listinfo/dri-devel
>
> --
> Sean Paul, Software Engineer, Google / Chromium OS