[Linux-kernel-mentees] [PATCH v2 02/12] fbdev: lxfb: use generic power management

Vaibhav Gupta vaibhavgupta40 at gmail.com
Mon Aug 10 18:57:13 UTC 2020


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.

Although the lxfb driver does not have that extra load, we should switch to
the new generic framework by updating function signatures and define a
"struct dev_pm_ops" variable to bind PM callbacks so that we can remove
the legacy .suspend & .resume bindings. Additionally, this helps us to
remove the unnecessary call to lxfb_suspend() in the event of Freeze and
Hibernate, as the function does nothing in their case.

Signed-off-by: Vaibhav Gupta <vaibhavgupta40 at gmail.com>
---
 drivers/video/fbdev/geode/lxfb.h      |  5 ----
 drivers/video/fbdev/geode/lxfb_core.c | 37 +++++++++++++++------------
 drivers/video/fbdev/geode/lxfb_ops.c  |  4 ---
 3 files changed, 20 insertions(+), 26 deletions(-)

diff --git a/drivers/video/fbdev/geode/lxfb.h b/drivers/video/fbdev/geode/lxfb.h
index ef24bf6d49dc..d37b32dbcd68 100644
--- a/drivers/video/fbdev/geode/lxfb.h
+++ b/drivers/video/fbdev/geode/lxfb.h
@@ -29,7 +29,6 @@ struct lxfb_par {
 	void __iomem *gp_regs;
 	void __iomem *dc_regs;
 	void __iomem *vp_regs;
-#ifdef CONFIG_PM
 	int powered_down;
 
 	/* register state, for power mgmt functionality */
@@ -50,7 +49,6 @@ struct lxfb_par {
 	uint32_t hcoeff[DC_HFILT_COUNT * 2];
 	uint32_t vcoeff[DC_VFILT_COUNT];
 	uint32_t vp_coeff[VP_COEFF_SIZE / 4];
-#endif
 };
 
 static inline unsigned int lx_get_pitch(unsigned int xres, int bpp)
@@ -64,11 +62,8 @@ int lx_blank_display(struct fb_info *, int);
 void lx_set_palette_reg(struct fb_info *, unsigned int, unsigned int,
 			unsigned int, unsigned int);
 
-#ifdef CONFIG_PM
 int lx_powerdown(struct fb_info *info);
 int lx_powerup(struct fb_info *info);
-#endif
-
 
 /* Graphics Processor registers (table 6-29 from the data book) */
 enum gp_registers {
diff --git a/drivers/video/fbdev/geode/lxfb_core.c b/drivers/video/fbdev/geode/lxfb_core.c
index adc2d9c2395e..66c81262d18f 100644
--- a/drivers/video/fbdev/geode/lxfb_core.c
+++ b/drivers/video/fbdev/geode/lxfb_core.c
@@ -443,17 +443,14 @@ static struct fb_info *lxfb_init_fbinfo(struct device *dev)
 	return info;
 }
 
-#ifdef CONFIG_PM
-static int lxfb_suspend(struct pci_dev *pdev, pm_message_t state)
+static int __maybe_unused lxfb_suspend(struct device *dev)
 {
-	struct fb_info *info = pci_get_drvdata(pdev);
+	struct fb_info *info = dev_get_drvdata(dev);
 
-	if (state.event == PM_EVENT_SUSPEND) {
-		console_lock();
-		lx_powerdown(info);
-		fb_set_suspend(info, 1);
-		console_unlock();
-	}
+	console_lock();
+	lx_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 */
@@ -461,9 +458,9 @@ static int lxfb_suspend(struct pci_dev *pdev, pm_message_t state)
 	return 0;
 }
 
-static int lxfb_resume(struct pci_dev *pdev)
+static int __maybe_unused lxfb_resume(struct device *dev)
 {
-	struct fb_info *info = pci_get_drvdata(pdev);
+	struct fb_info *info = dev_get_drvdata(dev);
 	int ret;
 
 	console_lock();
@@ -477,10 +474,6 @@ static int lxfb_resume(struct pci_dev *pdev)
 	console_unlock();
 	return 0;
 }
-#else
-#define lxfb_suspend NULL
-#define lxfb_resume NULL
-#endif
 
 static int lxfb_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 {
@@ -600,13 +593,23 @@ static struct pci_device_id lxfb_id_table[] = {
 
 MODULE_DEVICE_TABLE(pci, lxfb_id_table);
 
+static const struct dev_pm_ops lxfb_pm_ops = {
+#ifdef CONFIG_PM_SLEEP
+	.suspend	= lxfb_suspend,
+	.resume		= lxfb_resume,
+	.freeze		= NULL,
+	.thaw		= lxfb_resume,
+	.poweroff	= NULL,
+	.restore	= lxfb_resume,
+#endif
+};
+
 static struct pci_driver lxfb_driver = {
 	.name		= "lxfb",
 	.id_table	= lxfb_id_table,
 	.probe		= lxfb_probe,
 	.remove		= lxfb_remove,
-	.suspend	= lxfb_suspend,
-	.resume		= lxfb_resume,
+	.driver.pm	= &lxfb_pm_ops,
 };
 
 #ifndef MODULE
diff --git a/drivers/video/fbdev/geode/lxfb_ops.c b/drivers/video/fbdev/geode/lxfb_ops.c
index 5be8bc62844c..b3a041fce570 100644
--- a/drivers/video/fbdev/geode/lxfb_ops.c
+++ b/drivers/video/fbdev/geode/lxfb_ops.c
@@ -580,8 +580,6 @@ int lx_blank_display(struct fb_info *info, int blank_mode)
 	return 0;
 }
 
-#ifdef CONFIG_PM
-
 static void lx_save_regs(struct lxfb_par *par)
 {
 	uint32_t filt;
@@ -837,5 +835,3 @@ int lx_powerup(struct fb_info *info)
 	par->powered_down = 0;
 	return 0;
 }
-
-#endif
-- 
2.27.0



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