| Message ID | 20230901163944.RFT.3.I10dbe099fb1059d304ba847d19fc45054f7ffe9f@changeid (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm: drm-misc drivers call drm_atomic_helper_shutdown() at the right times | expand |
On Fri, 1 Sep 2023 16:39:54 -0700, 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. Among other things, this means that if a panel is in use that it > won't be cleanly powered off at system shutdown time. > > > [ ... ] Acked-by: Maxime Ripard <mripard@kernel.org> Thanks! Maxime
Hi, On Fri, Sep 1, 2023 at 4:40 PM Douglas Anderson <dianders@chromium.org> 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. 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 comes straight out of the kernel doc "driver > instance overview" in drm_drv.c. > > Suggested-by: Maxime Ripard <mripard@kernel.org> > Signed-off-by: Douglas Anderson <dianders@chromium.org> > --- > This commit is only compile-time tested. > > Though this patch could be squashed into the patch ("drm: Call > drm_atomic_helper_shutdown() at shutdown time for misc drivers"), I > kept it separate to call attention to this driver. While writing this > patch, I noticed that the bind() function is using "devm" and thus > assumes it doesn't need to do much explicit error handling. That's > actually a bug. As per kernel docs [1] "the lifetime of the aggregate > driver does not align with any of the underlying struct device > instances. Therefore devm cannot be used and all resources acquired or > allocated in this callback must be explicitly released in the unbind > callback". Fixing that is outside the scope of this commit. > > [1] https://docs.kernel.org/driver-api/component.html > > drivers/gpu/drm/vc4/vc4_drv.c | 36 ++++++++++++++++++++++------------- > 1 file changed, 23 insertions(+), 13 deletions(-) Landed to drm-misc-next: 013d382d11a2 drm/vc4: Call drm_atomic_helper_shutdown() at shutdown time
diff --git a/drivers/gpu/drm/vc4/vc4_drv.c b/drivers/gpu/drm/vc4/vc4_drv.c index 1b3531374967..c133e96b8aca 100644 --- a/drivers/gpu/drm/vc4/vc4_drv.c +++ b/drivers/gpu/drm/vc4/vc4_drv.c @@ -324,21 +324,21 @@ static int vc4_drm_bind(struct device *dev) if (!is_vc5) { ret = drmm_mutex_init(drm, &vc4->bin_bo_lock); if (ret) - return ret; + goto err; ret = vc4_bo_cache_init(drm); if (ret) - return ret; + goto err; } ret = drmm_mode_config_init(drm); if (ret) - return ret; + goto err; if (!is_vc5) { ret = vc4_gem_init(drm); if (ret) - return ret; + goto err; } node = of_find_compatible_node(NULL, NULL, "raspberrypi,bcm2835-firmware"); @@ -346,13 +346,15 @@ static int vc4_drm_bind(struct device *dev) firmware = rpi_firmware_get(node); of_node_put(node); - if (!firmware) - return -EPROBE_DEFER; + if (!firmware) { + ret = -EPROBE_DEFER; + goto err; + } } ret = drm_aperture_remove_framebuffers(driver); if (ret) - return ret; + goto err; if (firmware) { ret = rpi_firmware_property(firmware, @@ -366,32 +368,33 @@ static int vc4_drm_bind(struct device *dev) ret = component_bind_all(dev, drm); if (ret) - return ret; + goto err; ret = devm_add_action_or_reset(dev, vc4_component_unbind_all, vc4); if (ret) - return ret; + goto err; ret = vc4_plane_create_additional_planes(drm); if (ret) - goto unbind_all; + goto err; ret = vc4_kms_load(drm); if (ret < 0) - goto unbind_all; + goto err; drm_for_each_crtc(crtc, drm) vc4_crtc_disable_at_boot(crtc); ret = drm_dev_register(drm, 0); if (ret < 0) - goto unbind_all; + goto err; drm_fbdev_dma_setup(drm, 16); return 0; -unbind_all: +err: + platform_set_drvdata(pdev, NULL); return ret; } @@ -401,6 +404,7 @@ static void vc4_drm_unbind(struct device *dev) drm_dev_unplug(drm); drm_atomic_helper_shutdown(drm); + dev_set_drvdata(dev, NULL); } static const struct component_master_ops vc4_drm_ops = { @@ -444,6 +448,11 @@ static void vc4_platform_drm_remove(struct platform_device *pdev) component_master_del(&pdev->dev, &vc4_drm_ops); } +static void vc4_platform_drm_shutdown(struct platform_device *pdev) +{ + drm_atomic_helper_shutdown(platform_get_drvdata(pdev)); +} + static const struct of_device_id vc4_of_match[] = { { .compatible = "brcm,bcm2711-vc5", }, { .compatible = "brcm,bcm2835-vc4", }, @@ -455,6 +464,7 @@ MODULE_DEVICE_TABLE(of, vc4_of_match); static struct platform_driver vc4_platform_driver = { .probe = vc4_platform_drm_probe, .remove_new = vc4_platform_drm_remove, + .shutdown = vc4_platform_drm_shutdown, .driver = { .name = "vc4-drm", .of_match_table = vc4_of_match,
Based on grepping through the source code these drivers appear to be missing a call to drm_atomic_helper_shutdown() at system shutdown 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 comes straight out of the kernel doc "driver instance overview" in drm_drv.c. Suggested-by: Maxime Ripard <mripard@kernel.org> Signed-off-by: Douglas Anderson <dianders@chromium.org> --- This commit is only compile-time tested. Though this patch could be squashed into the patch ("drm: Call drm_atomic_helper_shutdown() at shutdown time for misc drivers"), I kept it separate to call attention to this driver. While writing this patch, I noticed that the bind() function is using "devm" and thus assumes it doesn't need to do much explicit error handling. That's actually a bug. As per kernel docs [1] "the lifetime of the aggregate driver does not align with any of the underlying struct device instances. Therefore devm cannot be used and all resources acquired or allocated in this callback must be explicitly released in the unbind callback". Fixing that is outside the scope of this commit. [1] https://docs.kernel.org/driver-api/component.html drivers/gpu/drm/vc4/vc4_drv.c | 36 ++++++++++++++++++++++------------- 1 file changed, 23 insertions(+), 13 deletions(-)