At Mon, 20 Dec 2010 16:34:36 +0000, Mark Brown wrote: > > On Mon, Dec 20, 2010 at 04:56:03PM +0100, Takashi Iwai wrote: > > Mark Brown wrote: > > > > It wasn't portability, it was specifically the fact that some drivers > > > want to do block operations which means they depend very strongly on the > > > exact memory layout of the cache (obviously this only works for > > > uncompressed caches). > > > But this is exactly what hinders the portability :) Which part of > > soc_4_12_spi_read/write specifies that this must be aligned to be BE > > while spi_7_9 to be LE? Why soc_16_16_i2c converts to BE internally > > while soc_16_8_i2c doesn't? I mean, such a difference isn't visible > > in the API level but hard-coded in the implementation although the > > API appears as if it's portable. > > They should all be specifying something, quite what they should be > specifying varies - it just comes down to whatever the standard wire > format that the chip vendors have come up with. Mostly if it's not > specified it should be little endian. > > It's not really been an issue as pretty much all the CPUs have the same > endianness. Yeah, I know it's working now. But it's hidden inside and merely called portable ;) > > > There's more potential users than currently have it enabled, it's just > > > that the WM8994 driver is the only driver that turns it on by default > > > right now (several other CODEC drivers should but need testing just to > > > confirm that it's OK). It's only a few kilobytes and Kconfig really > > > isn't good at supporting this sort of selection, I'd worry about the > > > usability issues. > > > Well, it drags LZO COMPRESS and DECOMPRESS unconditionally, which I > > feel uneasy. Usually the consumer of such lib stuff has a Kconfig, > > especially the feature can be optional (and in this case it is). > > > The necessary change is simple like below. The code that requires a > > compressed cache just needs to select SND_SOC_LZO_CACHE or whatever. > > That's one way of doing it, but it does hurt usability. That's a drawback, sure. > > It's no urgent issue, yeah. It's just what I feel uneasy to see such > > a thing... > > If someone's worried about memory usage in ASoC they'd be much better > going after the strings than this TBH. > > > +#ifdef CONFIG_SND_SOC_LZO_CACHE > > + SND_SOC_LZO_COMPRESSION = 2, > > +#endif > > +#ifdef CONFIG_SND_SOC_RBTREE_CACHE > > + SND_SOC_RBTREE_COMPRESSION = 3, > > +#endif > > If we were going to make this user selectable we should keep the defines > and then fall back to a flat cache if they're turned off otherwise you > end up having too much faff with Kconfig interdependencies. My intention of the chunk above was to give a build error for unsupported cache compressions. But fallback sounds also reasonable, too. > > config SND_SOC_WM8994 > > tristate > > + select SND_SOC_RBTREE_CACHE > > Except the machine driver can override this... Hmm, I thought the codec is always selected not depended? Can it be overridden? thanks, Takashi _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
