| Message ID | 20140217063510.21892.52120.sendpatchset@w520 (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Mon, Feb 17, 2014 at 7:35 AM, Magnus Damm <magnus.damm@gmail.com> wrote: > From: Magnus Damm <damm@opensource.se> > > Remove __init from rcar_gen2_read_mode_pins() to allow > it to be used after boot. For instance the R-Car Gen2 > MD21 check is needed even in the case of CPU Hotplug. This is a prerequisite for "[PATCH] ARM: shmobile: Check MD21 at SMP boot in case of APMU" > Signed-off-by: Magnus Damm <damm@opensource.se> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds
Hi Magnus, Thank you for the patch. On Monday 17 February 2014 15:35:10 Magnus Damm wrote: > From: Magnus Damm <damm@opensource.se> > > Remove __init from rcar_gen2_read_mode_pins() to allow > it to be used after boot. For instance the R-Car Gen2 > MD21 check is needed even in the case of CPU Hotplug. > > Signed-off-by: Magnus Damm <damm@opensource.se> > --- > > Written against renesas-devel-v3.14-rc2-20140213 > > arch/arm/mach-shmobile/setup-rcar-gen2.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > --- 0001/arch/arm/mach-shmobile/setup-rcar-gen2.c > +++ work/arch/arm/mach-shmobile/setup-rcar-gen2.c 2014-02-17 > 15:02:48.000000000 +0900 @@ -28,7 +28,7 @@ > > #define MODEMR 0xe6160060 > > -u32 __init rcar_gen2_read_mode_pins(void) > +u32 rcar_gen2_read_mode_pins(void) > { > void __iomem *modemr = ioremap_nocache(MODEMR, 4); > u32 mode; Should we read the value once at boot time and cache it ?
On Mon, Feb 17, 2014 at 11:59 AM, Laurent Pinchart <laurent.pinchart@ideasonboard.com> wrote: >> --- 0001/arch/arm/mach-shmobile/setup-rcar-gen2.c >> +++ work/arch/arm/mach-shmobile/setup-rcar-gen2.c 2014-02-17 >> 15:02:48.000000000 +0900 @@ -28,7 +28,7 @@ >> >> #define MODEMR 0xe6160060 >> >> -u32 __init rcar_gen2_read_mode_pins(void) >> +u32 rcar_gen2_read_mode_pins(void) >> { >> void __iomem *modemr = ioremap_nocache(MODEMR, 4); >> u32 mode; > > Should we read the value once at boot time and cache it ? That sounds like a great idea to me. The value doesn't change, and it avoids the ioremap()/iounmap() overhead on subsequent calls. Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds
Hi Laurent, On Mon, Feb 17, 2014 at 7:59 PM, Laurent Pinchart <laurent.pinchart@ideasonboard.com> wrote: > Hi Magnus, > > Thank you for the patch. > > On Monday 17 February 2014 15:35:10 Magnus Damm wrote: >> From: Magnus Damm <damm@opensource.se> >> >> Remove __init from rcar_gen2_read_mode_pins() to allow >> it to be used after boot. For instance the R-Car Gen2 >> MD21 check is needed even in the case of CPU Hotplug. >> >> Signed-off-by: Magnus Damm <damm@opensource.se> >> --- >> >> Written against renesas-devel-v3.14-rc2-20140213 >> >> arch/arm/mach-shmobile/setup-rcar-gen2.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> --- 0001/arch/arm/mach-shmobile/setup-rcar-gen2.c >> +++ work/arch/arm/mach-shmobile/setup-rcar-gen2.c 2014-02-17 >> 15:02:48.000000000 +0900 @@ -28,7 +28,7 @@ >> >> #define MODEMR 0xe6160060 >> >> -u32 __init rcar_gen2_read_mode_pins(void) >> +u32 rcar_gen2_read_mode_pins(void) >> { >> void __iomem *modemr = ioremap_nocache(MODEMR, 4); >> u32 mode; > > Should we read the value once at boot time and cache it ? Seems a bit of a micro-optimization to me, but sure, it can't hurt. Care to cook up an incremental patch implementing that? =) Cheers, / magnus
On Mon, Feb 17, 2014 at 08:16:47PM +0900, Magnus Damm wrote: > Hi Laurent, > > On Mon, Feb 17, 2014 at 7:59 PM, Laurent Pinchart > <laurent.pinchart@ideasonboard.com> wrote: > > Hi Magnus, > > > > Thank you for the patch. > > > > On Monday 17 February 2014 15:35:10 Magnus Damm wrote: > >> From: Magnus Damm <damm@opensource.se> > >> > >> Remove __init from rcar_gen2_read_mode_pins() to allow > >> it to be used after boot. For instance the R-Car Gen2 > >> MD21 check is needed even in the case of CPU Hotplug. > >> > >> Signed-off-by: Magnus Damm <damm@opensource.se> > >> --- > >> > >> Written against renesas-devel-v3.14-rc2-20140213 > >> > >> arch/arm/mach-shmobile/setup-rcar-gen2.c | 2 +- > >> 1 file changed, 1 insertion(+), 1 deletion(-) > >> > >> --- 0001/arch/arm/mach-shmobile/setup-rcar-gen2.c > >> +++ work/arch/arm/mach-shmobile/setup-rcar-gen2.c 2014-02-17 > >> 15:02:48.000000000 +0900 @@ -28,7 +28,7 @@ > >> > >> #define MODEMR 0xe6160060 > >> > >> -u32 __init rcar_gen2_read_mode_pins(void) > >> +u32 rcar_gen2_read_mode_pins(void) > >> { > >> void __iomem *modemr = ioremap_nocache(MODEMR, 4); > >> u32 mode; > > > > Should we read the value once at boot time and cache it ? > > Seems a bit of a micro-optimization to me, but sure, it can't hurt. > > Care to cook up an incremental patch implementing that? =) I have decided to take this patch as-is. Feel free to make incremental changes on top of it.
--- 0001/arch/arm/mach-shmobile/setup-rcar-gen2.c +++ work/arch/arm/mach-shmobile/setup-rcar-gen2.c 2014-02-17 15:02:48.000000000 +0900 @@ -28,7 +28,7 @@ #define MODEMR 0xe6160060 -u32 __init rcar_gen2_read_mode_pins(void) +u32 rcar_gen2_read_mode_pins(void) { void __iomem *modemr = ioremap_nocache(MODEMR, 4); u32 mode;