| Message ID | 1400308369-24375-1-git-send-email-Julia.Lawall@lip6.fr |
|---|---|
| State | Superseded |
| Headers | show |
On Sat, May 17, 2014 at 3:32 AM, Julia Lawall <Julia.Lawall@lip6.fr> wrote: > From: Julia Lawall <Julia.Lawall@lip6.fr> > > Platform_get_drvdata is an accessor function, and has no purpose if its > result is not used. > > The semantic patch that fixes this problem is as follows: > (http://coccinelle.lip6.fr/) > > // <smpl> > @@ > identifier x; > type T; > @@ > - T x = platform_get_drvdata(...); > ... when != x > // </smpl> > > Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr> > > --- > drivers/mtd/nand/bf5xx_nand.c | 4 ---- > 1 file changed, 4 deletions(-) > > diff --git a/drivers/mtd/nand/bf5xx_nand.c b/drivers/mtd/nand/bf5xx_nand.c > index b7a2494..b5fbd48 100644 > --- a/drivers/mtd/nand/bf5xx_nand.c > +++ b/drivers/mtd/nand/bf5xx_nand.c > @@ -840,15 +840,11 @@ out_err_kzalloc: > > static int bf5xx_nand_suspend(struct platform_device *dev, pm_message_t pm) > { > - struct bf5xx_nand_info *info = platform_get_drvdata(dev); > - > return 0; > } > > static int bf5xx_nand_resume(struct platform_device *dev) > { > - struct bf5xx_nand_info *info = platform_get_drvdata(dev); > - > return 0; In this case bf5xx_nand_suspend/resume could be removed?
On Sat, 17 May 2014, Fabio Estevam wrote: > On Sat, May 17, 2014 at 3:32 AM, Julia Lawall <Julia.Lawall@lip6.fr> wrote: > > From: Julia Lawall <Julia.Lawall@lip6.fr> > > > > Platform_get_drvdata is an accessor function, and has no purpose if its > > result is not used. > > > > The semantic patch that fixes this problem is as follows: > > (http://coccinelle.lip6.fr/) > > > > // <smpl> > > @@ > > identifier x; > > type T; > > @@ > > - T x = platform_get_drvdata(...); > > ... when != x > > // </smpl> > > > > Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr> > > > > --- > > drivers/mtd/nand/bf5xx_nand.c | 4 ---- > > 1 file changed, 4 deletions(-) > > > > diff --git a/drivers/mtd/nand/bf5xx_nand.c b/drivers/mtd/nand/bf5xx_nand.c > > index b7a2494..b5fbd48 100644 > > --- a/drivers/mtd/nand/bf5xx_nand.c > > +++ b/drivers/mtd/nand/bf5xx_nand.c > > @@ -840,15 +840,11 @@ out_err_kzalloc: > > > > static int bf5xx_nand_suspend(struct platform_device *dev, pm_message_t pm) > > { > > - struct bf5xx_nand_info *info = platform_get_drvdata(dev); > > - > > return 0; > > } > > > > static int bf5xx_nand_resume(struct platform_device *dev) > > { > > - struct bf5xx_nand_info *info = platform_get_drvdata(dev); > > - > > return 0; > > In this case bf5xx_nand_suspend/resume could be removed? I don't know. It looks like it is intentional to have a definition that returns an indication of success? The complete set of definitions is: #ifdef CONFIG_PM static int bf5xx_nand_suspend(struct platform_device *dev, pm_message_t pm) { struct bf5xx_nand_info *info = platform_get_drvdata(dev); return 0; } static int bf5xx_nand_resume(struct platform_device *dev) { struct bf5xx_nand_info *info = platform_get_drvdata(dev); return 0; } #else #define bf5xx_nand_suspend NULL #define bf5xx_nand_resume NULL #endif julia
+ Mike On Sat, May 17, 2014 at 03:12:02PM +0800, Julia Lawall wrote: > On Sat, 17 May 2014, Fabio Estevam wrote: > > On Sat, May 17, 2014 at 3:32 AM, Julia Lawall <Julia.Lawall@lip6.fr> wrote: > > > From: Julia Lawall <Julia.Lawall@lip6.fr> > > > > > > Platform_get_drvdata is an accessor function, and has no purpose if its > > > result is not used. > > > > > > The semantic patch that fixes this problem is as follows: > > > (http://coccinelle.lip6.fr/) > > > > > > // <smpl> > > > @@ > > > identifier x; > > > type T; > > > @@ > > > - T x = platform_get_drvdata(...); > > > ... when != x > > > // </smpl> > > > > > > Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr> > > > > > > --- > > > drivers/mtd/nand/bf5xx_nand.c | 4 ---- > > > 1 file changed, 4 deletions(-) > > > > > > diff --git a/drivers/mtd/nand/bf5xx_nand.c b/drivers/mtd/nand/bf5xx_nand.c > > > index b7a2494..b5fbd48 100644 > > > --- a/drivers/mtd/nand/bf5xx_nand.c > > > +++ b/drivers/mtd/nand/bf5xx_nand.c > > > @@ -840,15 +840,11 @@ out_err_kzalloc: > > > > > > static int bf5xx_nand_suspend(struct platform_device *dev, pm_message_t pm) > > > { > > > - struct bf5xx_nand_info *info = platform_get_drvdata(dev); > > > - > > > return 0; > > > } > > > > > > static int bf5xx_nand_resume(struct platform_device *dev) > > > { > > > - struct bf5xx_nand_info *info = platform_get_drvdata(dev); > > > - > > > return 0; > > > > In this case bf5xx_nand_suspend/resume could be removed? > > I don't know. It looks like it is intentional to have a definition that > returns an indication of success? The complete set of definitions is: I'm not so sure. I believe suspend/resume works just fine without the hooks, if those hooks would otherwise be doing nothing. It is notable that this driver is not using the modern dev_pm_ops form of the suspend/resume callbacks, so maybe it just hasn't aged gracefully--and possibly was never supported properly in the first place. I'll either take this patch as-is, or look to killing off the suspend/resume callbacks entirely here, depending on Mike's feedback. > #ifdef CONFIG_PM > > static int bf5xx_nand_suspend(struct platform_device *dev, pm_message_t > pm) > { > struct bf5xx_nand_info *info = platform_get_drvdata(dev); > > return 0; > } > > static int bf5xx_nand_resume(struct platform_device *dev) > { > struct bf5xx_nand_info *info = platform_get_drvdata(dev); > > return 0; > } > > #else > #define bf5xx_nand_suspend NULL > #define bf5xx_nand_resume NULL > #endif Thanks, Brian
On Tue, May 20, 2014 at 01:35:31AM -0700, Brian Norris wrote: > > > > static int bf5xx_nand_resume(struct platform_device *dev) > > > > { > > > > - struct bf5xx_nand_info *info = platform_get_drvdata(dev); > > > > - > > > > return 0; > > > > > > In this case bf5xx_nand_suspend/resume could be removed? > > > > I don't know. It looks like it is intentional to have a definition that > > returns an indication of success? The complete set of definitions is: > > I'm not so sure. I believe suspend/resume works just fine without the > hooks, if those hooks would otherwise be doing nothing. It is notable > that this driver is not using the modern dev_pm_ops form of the > suspend/resume callbacks, so maybe it just hasn't aged gracefully--and > possibly was never supported properly in the first place. > These are called from platform_legacy_suspend/platform_legacy_resume. It looks like the functions are not needed. (I am not an expert on pm, I just querried my Smatch Cross Function Database which is awesome). regards, dan carpenter
diff --git a/drivers/mtd/nand/bf5xx_nand.c b/drivers/mtd/nand/bf5xx_nand.c index b7a2494..b5fbd48 100644 --- a/drivers/mtd/nand/bf5xx_nand.c +++ b/drivers/mtd/nand/bf5xx_nand.c @@ -840,15 +840,11 @@ out_err_kzalloc: static int bf5xx_nand_suspend(struct platform_device *dev, pm_message_t pm) { - struct bf5xx_nand_info *info = platform_get_drvdata(dev); - return 0; } static int bf5xx_nand_resume(struct platform_device *dev) { - struct bf5xx_nand_info *info = platform_get_drvdata(dev); - return 0; }