From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sam Ravnborg Date: Sun, 16 Aug 2020 20:24:42 +0000 Subject: Re: [PATCH v2 09/12] fbdev: i740fb: use generic power management Message-Id: <20200816202442.GB1426650@ravnborg.org> List-Id: References: <20200810165458.GA292825@ravnborg.org> <20200810185723.15540-1-vaibhavgupta40@gmail.com> <20200810185723.15540-10-vaibhavgupta40@gmail.com> In-Reply-To: <20200810185723.15540-10-vaibhavgupta40@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Vaibhav Gupta Cc: linux-fbdev@vger.kernel.org, linux-kernel@vger.kernel.org, Bartlomiej Zolnierkiewicz , Vaibhav Gupta , Shuah Khan , Russell King , dri-devel@lists.freedesktop.org, linux-geode@lists.infradead.org, Bjorn Helgaas , Bjorn Helgaas , Andres Salomon , Bjorn Helgaas , Paul Mackerras , linux-kernel-mentees@lists.linuxfoundation.org, linux-arm-kernel@lists.infradead.org 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 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 > --- > 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