Re: [PATCH 2/2] sis7019: add support for pre-2.6 kernels

From: Takashi Iwai <tiwai@suse.de>
To: Dave Dillow <dave@thedillows.org>
Cc: alsa-devel@alsa-project.org
Subject: Re: [PATCH 2/2] sis7019: add support for pre-2.6 kernels
Date: Wed, 28 Nov 2007 10:41:05 +0100	[thread overview]
Message-ID: <s5hfxyqiu6m.wl%tiwai@suse.de> (raw)
In-Reply-To: <1196234352.7017.32.camel@obelisk.thedillows.org>

At Wed, 28 Nov 2007 02:19:12 -0500,
Dave Dillow wrote:
> 
> The sis7019 driver uses __ffs(), which is available in 2.6 kernels, but
> not in most earlier ones. This patches the driver to use a local version
> assembly version, as the hardware is SiS 55x only (i486/Pentium-ish).

Then it'd be better to add the dependency on CONFIG_X86_32 so that it
won't be compiled on other architectures.

Also, replace __ffs() only for 2.4 kernels, e.g.

	#if LINUX_VERSION_CODE >= KERNE_VERSION(2, 6, 0)
		bit = __ffs(status);
	#else
		bit = sis_ffs(status);
	#endif

Thanks,

Takashi

> Signed-off-by: David Dillow <dave@thedillows.org>
> ---
> This is against the alsa-driver hg repo. I've not build tested this
> version, as the build system currently hates me. However, this is 95%
> identical to what I was using against 1.0.13. Only the location of the
> __ffs -> sis_ffs change is different.
> 
>  pci/sis7019.patch   |   32 ++++++++++++++++++++++++++++++++
>  pci/Makefile        |    3 ++-
>  2 files changed, 34 insertions(+), 1 deletion(-)
> 
> diff -r ab42d23439ef pci/Makefile
> --- a/pci/Makefile	Tue Nov 27 16:05:25 2007 +0100
> +++ b/pci/Makefile	Wed Nov 28 01:39:04 2007 -0500
> @@ -10,7 +10,7 @@ include $(SND_TOPDIR)/Makefile.conf
>  #
>  
>  clean-files := ad1889.c atiixp.c atiixp_modem.c bt87x.c cmipci.c ens1370.c \
> -	fm801.c intel8x0.c maestro3.c via82xx.c via82xx_modem.c
> +	fm801.c intel8x0.c maestro3.c sis7019.c via82xx.c via82xx_modem.c
>  
>  obj-$(CONFIG_SND) += pdplus/ asihpi/ oxygen/
>  
> @@ -31,5 +31,6 @@ fm801.c: fm801.patch $(SND_TOPDIR)/alsa-
>  fm801.c: fm801.patch $(SND_TOPDIR)/alsa-kernel/pci/fm801.c
>  intel8x0.c: intel8x0.patch $(SND_TOPDIR)/alsa-kernel/pci/intel8x0.c
>  maestro3.c: maestro3.patch $(SND_TOPDIR)/alsa-kernel/pci/maestro3.c
> +sis7019.c: sis7019.patch $(SND_TOPDIR)/alsa-kernel/pci/sis7019.c
>  via82xx.c: via82xx.patch $(SND_TOPDIR)/alsa-kernel/pci/via82xx.c
>  via82xx_modem.c: via82xx_modem.patch $(SND_TOPDIR)/alsa-kernel/pci/via82xx_modem.c
> diff -r ab42d23439ef pci/sis7019.patch
> --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
> +++ b/pci/sis7019.patch	Wed Nov 28 01:39:04 2007 -0500
> @@ -0,0 +1,32 @@
> +--- ../alsa-kernel/pci/sis7019.c	2007-11-28 01:02:26.000000000 -0500
> ++++ sis7019.c	2007-11-28 01:36:27.000000000 -0500
> +@@ -33,6 +33,14 @@
> + #include <sound/initval.h>
> + #include "sis7019.h"
> + 
> ++static inline unsigned long sis_ffs(unsigned long word)
> ++{
> ++	__asm__("bsfl %1,%0"
> ++		:"=r" (word)
> ++		:"rm" (word));
> ++	return word;
> ++}
> ++
> + MODULE_AUTHOR("David Dillow <dave@thedillows.org>");
> + MODULE_DESCRIPTION("SiS 7019");
> + MODULE_LICENSE("GPL");
> +@@ -289,7 +297,7 @@
> + 	int bit;
> + 
> + 	while (status) {
> +-		bit = __ffs(status);
> ++		bit = sis_ffs(status);
> + 		status >>= bit + 1;
> + 		voice += bit;
> + 		sis_update_voice(voice);
> +@@ -1464,3 +1472,5 @@
> + 
> + module_init(sis7019_init);
> + module_exit(sis7019_exit);
> ++
> ++EXPORT_NO_SYMBOLS
> 
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