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 68E7DC433DF for ; Mon, 10 Aug 2020 16:55:16 +0000 (UTC) Received: from silver.osuosl.org (smtp3.osuosl.org [140.211.166.136]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 23CA020829 for ; Mon, 10 Aug 2020 16:55:15 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 23CA020829 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ravnborg.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linux-kernel-mentees-bounces@lists.linuxfoundation.org Received: from localhost (localhost [127.0.0.1]) by silver.osuosl.org (Postfix) with ESMTP id BEAF4204AF; Mon, 10 Aug 2020 16:55:15 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from silver.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id T7dc6-T50uv3; Mon, 10 Aug 2020 16:55:11 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by silver.osuosl.org (Postfix) with ESMTP id 25E3320401; Mon, 10 Aug 2020 16:55:11 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 0D057C013C; Mon, 10 Aug 2020 16:55:11 +0000 (UTC) Received: from whitealder.osuosl.org (smtp1.osuosl.org [140.211.166.138]) by lists.linuxfoundation.org (Postfix) with ESMTP id B7B37C004D for ; Mon, 10 Aug 2020 16:55:09 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by whitealder.osuosl.org (Postfix) with ESMTP id B266088BFF for ; Mon, 10 Aug 2020 16:55:09 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from whitealder.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 9Nmbp2VPIopX for ; Mon, 10 Aug 2020 16:55:07 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from asavdk4.altibox.net (asavdk4.altibox.net [109.247.116.15]) by whitealder.osuosl.org (Postfix) with ESMTPS id 6FC6D88C00 for ; Mon, 10 Aug 2020 16:55:07 +0000 (UTC) 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 3A159804D9; Mon, 10 Aug 2020 18:55:00 +0200 (CEST) Date: Mon, 10 Aug 2020 18:54:58 +0200 From: Sam Ravnborg To: Vaibhav Gupta Message-ID: <20200810165458.GA292825@ravnborg.org> References: <20200805180722.244008-1-vaibhavgupta40@gmail.com> <20200805180722.244008-2-vaibhavgupta40@gmail.com> <20200808111746.GA24172@ravnborg.org> <20200810093948.GB6615@gmail.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20200810093948.GB6615@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=3wanNKNTOeUfviNiXn8A:9 a=CjuIK1q_8ugA:10 a=Vxmtnl_E_bksehYqCbjh:22 Cc: linux-fbdev@vger.kernel.org, Antonino Daplas , Bartlomiej Zolnierkiewicz , Vaibhav Gupta , Florian Tobias Schandinat , Russell King , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, Bjorn Helgaas , linux-arm-kernel@lists.infradead.org, Andres Salomon , Bjorn Helgaas , Paul Mackerras , linux-kernel-mentees@lists.linuxfoundation.org, linux-geode@lists.infradead.org Subject: Re: [Linux-kernel-mentees] [PATCH v1 01/12] fbdev: gxfb: use generic power management X-BeenThere: linux-kernel-mentees@lists.linuxfoundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: linux-kernel-mentees-bounces@lists.linuxfoundation.org Sender: "Linux-kernel-mentees" Hi Vaibhav On Mon, Aug 10, 2020 at 03:09:48PM +0530, Vaibhav Gupta wrote: > On Sat, Aug 08, 2020 at 01:17:46PM +0200, Sam Ravnborg wrote: > > 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? > > > Yeah, the commit messages are bit misleading, I have modified them. > > > > > > 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. > > > gxfb_probe() invokes pci_set_drvdata(pdev, info) which in turn calls > dev_set_drvdata(&pdev->dev, data). Adding dev_get_drvdata() will be redundant. OK, not obvious but you are right that calling dev_get_drvdata() would be redundant and no need. There is a pci_get_drvdata() user left so we cannot just skip it and use the dev_set_drvdata() direct. > > > > > > > - 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. > > > Earlier, gxfb_suspend() performed each operation just for suspend event. > And as it was legacy code, it was invoked by pci_legacy_suspend() for > pci_pm_suspend(), pci_pm_freeze() and pci_pm_poweroff(). > Thus, the code was wrapped inside "if" container: > if (state.event == PM_EVENT_SUSPEND) { } > > After binding it with dev_pm_ops variable, pm->suspend() is invoked by just > pci_pm_suspend() which is required. > > So I removed the "if" container and bind the callback with pm->suspend pointer > only. Looking at platform.c I got the impression that freeze() would call pci_legacy_suspend() anyway - but I may have missind something. So I guess this is OK then. I look forward for next revision with updated changelogs. Sam > > Using SET_SYSTEM_PM_OPS will bring back the extra step of invoking gxfb_suspend() > for freeze and poweroff, even though the function will do nothing in that case. > > Vaibhav Gupta > > 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 _______________________________________________ Linux-kernel-mentees mailing list Linux-kernel-mentees@lists.linuxfoundation.org https://lists.linuxfoundation.org/mailman/listinfo/linux-kernel-mentees