From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-10.0 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id DFCFAC433DF for ; Sat, 8 Aug 2020 11:18:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C2E6E20855 for ; Sat, 8 Aug 2020 11:18:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726240AbgHHLSr (ORCPT ); Sat, 8 Aug 2020 07:18:47 -0400 Received: from asavdk4.altibox.net ([109.247.116.15]:55688 "EHLO asavdk4.altibox.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726076AbgHHLR6 (ORCPT ); Sat, 8 Aug 2020 07:17:58 -0400 Received: from ravnborg.org (unknown [188.228.123.71]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by asavdk4.altibox.net (Postfix) with ESMTPS id 532A58053B; Sat, 8 Aug 2020 13:17:48 +0200 (CEST) Date: Sat, 8 Aug 2020 13:17:46 +0200 From: Sam Ravnborg To: Vaibhav Gupta Cc: Bjorn Helgaas , Bjorn Helgaas , Bjorn Helgaas , Vaibhav Gupta , Bartlomiej Zolnierkiewicz , Paul Mackerras , Russell King , Andres Salomon , Antonino Daplas , Florian Tobias Schandinat , linux-fbdev@vger.kernel.org, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-geode@lists.infradead.org, Shuah Khan , linux-kernel-mentees@lists.linuxfoundation.org, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH v1 01/12] fbdev: gxfb: use generic power management Message-ID: <20200808111746.GA24172@ravnborg.org> References: <20200805180722.244008-1-vaibhavgupta40@gmail.com> <20200805180722.244008-2-vaibhavgupta40@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200805180722.244008-2-vaibhavgupta40@gmail.com> X-CMAE-Score: 0 X-CMAE-Analysis: v=2.3 cv=aP3eV41m c=1 sm=1 tr=0 a=S6zTFyMACwkrwXSdXUNehg==:117 a=S6zTFyMACwkrwXSdXUNehg==:17 a=kj9zAlcOel0A:10 a=pGLkceISAAAA:8 a=e5mUnYsNAAAA:8 a=wbgKA9Bdv8qsLKdzXcgA:9 a=CjuIK1q_8ugA:10 a=Vxmtnl_E_bksehYqCbjh:22 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Vaibhav On Wed, Aug 05, 2020 at 11:37:11PM +0530, Vaibhav Gupta wrote: > Drivers using legacy power management .suspen()/.resume() callbacks > have to manage PCI states and device's PM states themselves. They also > need to take care of standard configuration registers. > > Switch to generic power management framework using a single > "struct dev_pm_ops" variable "to take the unnecessary load from the driver." - I do not parse the above - I cannot see what load is removed. But the code is simpler which is fine. The drawback is that we now always link in the suspend_gx functions but hopefultl the linker drops them later. > This also avoids the need for the driver to directly call most of the PCI > helper functions and device power state control functions, as through > the generic framework PCI Core takes care of the necessary operations, > and drivers are required to do only device-specific jobs. Again, I do not see what calles are removed. A single check for the state is dropped - anything else? > > Signed-off-by: Vaibhav Gupta > --- > drivers/video/fbdev/geode/gxfb.h | 5 ---- > drivers/video/fbdev/geode/gxfb_core.c | 36 ++++++++++++++------------ > drivers/video/fbdev/geode/suspend_gx.c | 4 --- > 3 files changed, 20 insertions(+), 25 deletions(-) > > diff --git a/drivers/video/fbdev/geode/gxfb.h b/drivers/video/fbdev/geode/gxfb.h > index d2e9c5c8e294..792c111c21e4 100644 > --- a/drivers/video/fbdev/geode/gxfb.h > +++ b/drivers/video/fbdev/geode/gxfb.h > @@ -21,7 +21,6 @@ struct gxfb_par { > void __iomem *dc_regs; > void __iomem *vid_regs; > void __iomem *gp_regs; > -#ifdef CONFIG_PM > int powered_down; > > /* register state, for power management functionality */ > @@ -36,7 +35,6 @@ struct gxfb_par { > uint64_t fp[FP_REG_COUNT]; > > uint32_t pal[DC_PAL_COUNT]; > -#endif > }; > > unsigned int gx_frame_buffer_size(void); > @@ -49,11 +47,8 @@ void gx_set_dclk_frequency(struct fb_info *info); > void gx_configure_display(struct fb_info *info); > int gx_blank_display(struct fb_info *info, int blank_mode); > > -#ifdef CONFIG_PM > int gx_powerdown(struct fb_info *info); > int gx_powerup(struct fb_info *info); > -#endif > - > > /* Graphics Processor registers (table 6-23 from the data book) */ > enum gp_registers { > diff --git a/drivers/video/fbdev/geode/gxfb_core.c b/drivers/video/fbdev/geode/gxfb_core.c > index d38a148d4746..44089b331f91 100644 > --- a/drivers/video/fbdev/geode/gxfb_core.c > +++ b/drivers/video/fbdev/geode/gxfb_core.c > @@ -322,17 +322,14 @@ static struct fb_info *gxfb_init_fbinfo(struct device *dev) > return info; > } > > -#ifdef CONFIG_PM > -static int gxfb_suspend(struct pci_dev *pdev, pm_message_t state) > +static int __maybe_unused gxfb_suspend(struct device *dev) > { > - struct fb_info *info = pci_get_drvdata(pdev); > + struct fb_info *info = dev_get_drvdata(dev); I do not see any dev_set_drvdata() so I guess we get a NULL pointer here which is not intended. Adding a dev_set_data() to gxfb_probe() would do the trick. > > - if (state.event == PM_EVENT_SUSPEND) { > - console_lock(); > - gx_powerdown(info); > - fb_set_suspend(info, 1); > - console_unlock(); > - } > + console_lock(); > + gx_powerdown(info); > + fb_set_suspend(info, 1); > + console_unlock(); > > /* there's no point in setting PCI states; we emulate PCI, so > * we don't end up getting power savings anyways */ > @@ -340,9 +337,9 @@ static int gxfb_suspend(struct pci_dev *pdev, pm_message_t state) > return 0; > } > > -static int gxfb_resume(struct pci_dev *pdev) > +static int __maybe_unused gxfb_resume(struct device *dev) > { > - struct fb_info *info = pci_get_drvdata(pdev); > + struct fb_info *info = dev_get_drvdata(dev); > int ret; > > console_lock(); > @@ -356,7 +353,6 @@ static int gxfb_resume(struct pci_dev *pdev) > console_unlock(); > return 0; > } > -#endif > > static int gxfb_probe(struct pci_dev *pdev, const struct pci_device_id *id) > { > @@ -467,15 +463,23 @@ static const struct pci_device_id gxfb_id_table[] = { > > MODULE_DEVICE_TABLE(pci, gxfb_id_table); > > +static const struct dev_pm_ops gxfb_pm_ops = { > +#ifdef CONFIG_PM_SLEEP > + .suspend = gxfb_suspend, > + .resume = gxfb_resume, > + .freeze = NULL, > + .thaw = gxfb_resume, > + .poweroff = NULL, > + .restore = gxfb_resume, > +#endif > +}; Can we use SET_SYSTEM_SLEEP_PM_OPS here? .freeze will be assigned gxfb_suspend, but gxfb_suspend will anyway be called as far as I read the code. Likewise for poweroff. Sam > + > static struct pci_driver gxfb_driver = { > .name = "gxfb", > .id_table = gxfb_id_table, > .probe = gxfb_probe, > .remove = gxfb_remove, > -#ifdef CONFIG_PM > - .suspend = gxfb_suspend, > - .resume = gxfb_resume, > -#endif > + .driver.pm = &gxfb_pm_ops, > }; > > #ifndef MODULE > diff --git a/drivers/video/fbdev/geode/suspend_gx.c b/drivers/video/fbdev/geode/suspend_gx.c > index 1110a527c35c..8c49d4e98772 100644 > --- a/drivers/video/fbdev/geode/suspend_gx.c > +++ b/drivers/video/fbdev/geode/suspend_gx.c > @@ -11,8 +11,6 @@ > > #include "gxfb.h" > > -#ifdef CONFIG_PM > - > static void gx_save_regs(struct gxfb_par *par) > { > int i; > @@ -259,5 +257,3 @@ int gx_powerup(struct fb_info *info) > par->powered_down = 0; > return 0; > } > - > -#endif > -- > 2.27.0 > > _______________________________________________ > dri-devel mailing list > dri-devel@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/dri-devel