Re: [Linux-kernel-mentees] [PATCH v2 09/12] fbdev: i740fb: use generic power management
From: Sam Ravnborg <hidden>
Date: 2020-08-16 20:24:50
Also in:
dri-devel, linux-arm-kernel, linux-fbdev, lkml
Hi Vaibhav On Tue, Aug 11, 2020 at 12:27:20AM +0530, Vaibhav Gupta wrote:
Drivers should do only device-specific jobs. But in general, drivers using legacy PCI PM framework for .suspend()/.resume() have to manage many PCI PM-related tasks themselves which can be done by PCI Core itself. This brings extra load on the driver and it directly calls PCI helper functions to handle them. Switch to the new generic framework by updating function signatures and define a "struct dev_pm_ops" variable to bind PM callbacks. Also, remove unnecessary calls to the PCI Helper functions along with the legacy .suspend & .resume bindings. Signed-off-by: Vaibhav Gupta <vaibhavgupta40@gmail.com>
I several of the drivers I briefly looked at a new set of helpers were introduced for the different types of pm actions. They then called a more generic function that uses the passes enumeration to decide what to do. But in this driver the test "state.event == PM_EVENT_FREEZE" is dropped and there is no freeze operation. Please explain this change so the reader is not left wondering. Sam
quoted hunk ↗ jump to hunk
--- drivers/video/fbdev/i740fb.c | 40 +++++++++++++++--------------------- 1 file changed, 16 insertions(+), 24 deletions(-)diff --git a/drivers/video/fbdev/i740fb.c b/drivers/video/fbdev/i740fb.c index c65ec7386e87..8d7f06fc8a5a 100644 --- a/drivers/video/fbdev/i740fb.c +++ b/drivers/video/fbdev/i740fb.c@@ -1175,16 +1175,11 @@ static void i740fb_remove(struct pci_dev *dev) } } -#ifdef CONFIG_PM -static int i740fb_suspend(struct pci_dev *dev, pm_message_t state) +static int __maybe_unused i740fb_suspend(struct device *dev) { - struct fb_info *info = pci_get_drvdata(dev); + struct fb_info *info = dev_get_drvdata(dev); struct i740fb_par *par = info->par; - /* don't disable console during hibernation and wakeup from it */ - if (state.event == PM_EVENT_FREEZE || state.event == PM_EVENT_PRETHAW) - return 0; - console_lock(); mutex_lock(&(par->open_lock));@@ -1197,19 +1192,15 @@ static int i740fb_suspend(struct pci_dev *dev, pm_message_t state) fb_set_suspend(info, 1); - pci_save_state(dev); - pci_disable_device(dev); - pci_set_power_state(dev, pci_choose_state(dev, state)); - mutex_unlock(&(par->open_lock)); console_unlock(); return 0; } -static int i740fb_resume(struct pci_dev *dev) +static int __maybe_unused i740fb_resume(struct device *dev) { - struct fb_info *info = pci_get_drvdata(dev); + struct fb_info *info = dev_get_drvdata(dev); struct i740fb_par *par = info->par; console_lock();@@ -1218,11 +1209,6 @@ static int i740fb_resume(struct pci_dev *dev) if (par->ref_count == 0) goto fail; - pci_set_power_state(dev, PCI_D0); - pci_restore_state(dev); - if (pci_enable_device(dev)) - goto fail; - i740fb_set_par(info); fb_set_suspend(info, 0);@@ -1231,10 +1217,17 @@ static int i740fb_resume(struct pci_dev *dev) console_unlock(); return 0; } -#else -#define i740fb_suspend NULL -#define i740fb_resume NULL -#endif /* CONFIG_PM */ + +static const struct dev_pm_ops i740fb_pm_ops = { +#ifdef CONFIG_PM_SLEEP + .suspend = i740fb_suspend, + .resume = i740fb_resume, + .freeze = NULL, + .thaw = i740fb_resume, + .poweroff = i740fb_suspend, + .restore = i740fb_resume, +#endif /* CONFIG_PM_SLEEP */ +}; #define I740_ID_PCI 0x00d1 #define I740_ID_AGP 0x7800@@ -1251,8 +1244,7 @@ static struct pci_driver i740fb_driver = { .id_table = i740fb_id_table, .probe = i740fb_probe, .remove = i740fb_remove, - .suspend = i740fb_suspend, - .resume = i740fb_resume, + .driver.pm = &i740fb_pm_ops, }; #ifndef MODULE-- 2.27.0
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