Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [PATCH 4.4 33/46] drm/nouveau: Dont enabling polling twice on runtime resume | Date | Thu, 15 Jun 2017 19:52:52 +0200 |
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4.4-stable review patch. If anyone has any objections, please let me know.
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From: Lyude Paul <lyude@redhat.com>
[ Upstream commit cae9ff036eea577856d5b12860b4c79c5e71db4a ]
As it turns out, on cards that actually have CRTCs on them we're already calling drm_kms_helper_poll_enable(drm_dev) from nouveau_display_resume() before we call it in nouveau_pmops_runtime_resume(). This leads us to accidentally trying to enable polling twice, which results in a potential deadlock between the RPM locks and drm_dev->mode_config.mutex if we end up trying to enable polling the second time while output_poll_execute is running and holding the mode_config lock. As such, make sure we only enable polling in nouveau_pmops_runtime_resume() if we need to.
This fixes hangs observed on the ThinkPad W541
Signed-off-by: Lyude <lyude@redhat.com> Cc: Hans de Goede <hdegoede@redhat.com> Cc: Kilian Singer <kilian.singer@quantumtechnology.info> Cc: Lukas Wunner <lukas@wunner.de> Cc: David Airlie <airlied@redhat.com> Signed-off-by: Dave Airlie <airlied@redhat.com> Signed-off-by: Sasha Levin <alexander.levin@verizon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- drivers/gpu/drm/nouveau/nouveau_display.c | 3 ++- drivers/gpu/drm/nouveau/nouveau_drm.c | 5 ++++- 2 files changed, 6 insertions(+), 2 deletions(-)
--- a/drivers/gpu/drm/nouveau/nouveau_display.c +++ b/drivers/gpu/drm/nouveau/nouveau_display.c @@ -370,7 +370,8 @@ nouveau_display_init(struct drm_device * return ret; /* enable polling for external displays */ - drm_kms_helper_poll_enable(dev); + if (!dev->mode_config.poll_enabled) + drm_kms_helper_poll_enable(dev); /* enable hotplug interrupts */ list_for_each_entry(connector, &dev->mode_config.connector_list, head) { --- a/drivers/gpu/drm/nouveau/nouveau_drm.c +++ b/drivers/gpu/drm/nouveau/nouveau_drm.c @@ -743,7 +743,10 @@ nouveau_pmops_runtime_resume(struct devi pci_set_master(pdev); ret = nouveau_do_resume(drm_dev, true); - drm_kms_helper_poll_enable(drm_dev); + + if (!drm_dev->mode_config.poll_enabled) + drm_kms_helper_poll_enable(drm_dev); + /* do magic */ nvif_mask(&device->object, 0x088488, (1 << 25), (1 << 25)); vga_switcheroo_set_dynamic_switch(pdev, VGA_SWITCHEROO_ON);
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