On the MacBook Pro, power of the gpu is cut by a gmux chip. Sometimes the gpu gets stuck in powersaving mode and refuses to wake up ("Refused to change power state, currently in D3"). Inserting a delay between setting the gpu to D3hot and cutting the power seems to help (most of the time). This issue and its (partial) remediation by the patch was observed with an Nvidia GT650M (NVE7 / GK107).
Signed-off-by: Lukas Wunner lukas@wunner.de --- drivers/gpu/drm/nouveau/nouveau_drm.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/drivers/gpu/drm/nouveau/nouveau_drm.c b/drivers/gpu/drm/nouveau/nouveau_drm.c index 8904933..649024d 100644 --- a/drivers/gpu/drm/nouveau/nouveau_drm.c +++ b/drivers/gpu/drm/nouveau/nouveau_drm.c @@ -23,6 +23,7 @@ */
#include <linux/console.h> +#include <linux/delay.h> #include <linux/module.h> #include <linux/pci.h> #include <linux/pm_runtime.h> @@ -666,6 +667,7 @@ nouveau_pmops_suspend(struct device *dev) pci_save_state(pdev); pci_disable_device(pdev); pci_set_power_state(pdev, PCI_D3hot); + udelay(200); return 0; }