On 5/12/20 8:46 AM, Alex Deucher wrote:
On Mon, May 11, 2020 at 6:37 PM Pierre-Louis Bossart pierre-louis.bossart@linux.intel.com wrote:
@@ -233,6 +234,11 @@ static int snd_rn_acp_probe(struct pci_dev *pci, ret = PTR_ERR(adata->pdev); goto unregister_devs; }
pm_runtime_set_autosuspend_delay(&pci->dev, ACP_SUSPEND_DELAY_MS);pm_runtime_use_autosuspend(&pci->dev);pm_runtime_allow(&pci->dev);pm_runtime_mark_last_busy(&pci->dev);pm_runtime_put_autosuspend(&pci->dev);usually there is a pm_runtime_put_noidle() here?
I'm not sure.
[...]
static void snd_rn_acp_remove(struct pci_dev *pci) { struct acp_dev_data *adata; @@ -260,6 +302,9 @@ static void snd_rn_acp_remove(struct pci_dev *pci) ret = rn_acp_deinit(adata->acp_base); if (ret) dev_err(&pci->dev, "ACP de-init failed\n");
pm_runtime_put_noidle(&pci->dev);pm_runtime_get_sync(&pci->dev);pm_runtime_forbid(&pci->dev);doing a put_noidle() followed by a get_sync() and immediately forbid() is very odd at best. Isn't the recommendation to call get_noresume() here?
I'm not sure here either. Is there some definitive documentation on what exact sequences are supposed to be used in drivers? A quick browse through drivers that implement runtime pm seems to show a lot of variation. This sequence works. I'm not sure if it's optimal or not.
We based our sequence on the comments in drivers/pci/pci-driver.c
/* * Unbound PCI devices are always put in D0, regardless of * runtime PM status. During probe, the device is set to * active and the usage count is incremented. If the driver * supports runtime PM, it should call pm_runtime_put_noidle(), * or any other runtime PM helper function decrementing the usage * count, in its probe routine and pm_runtime_get_noresume() in * its remove routine. */