2011/5/22 Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxxxx>: > On Wed, May 11, 2011 at 05:29:02PM +0100, Russell King - ARM Linux wrote: >> On Wed, May 11, 2011 at 08:54:46AM -0700, Greg KH wrote: >> > On Wed, May 11, 2011 at 08:39:54AM +0200, Uwe Kleine-König wrote: >> > > Hello Greg, >> > > >> > > On Fri, May 06, 2011 at 11:00:05AM +0200, Uwe Kleine-König wrote: >> > > > Commit >> > > > >> > > > 09ba0de (USB: fsl_udc_core: prepare for SoCs with BE registers and descriptors) >> > > > >> > > > introduced two function pointers _fsl_readl and _fsl_writel in an #ifdef >> > > > CONFIG_PPC32 block and used then unconditionally in fsl_udc_probe. >> > > > To make the driver compile again this use has to be protected by >> > > > an #ifdef, too. Moreover ARM doesn't have flush_dcache_range so this >> > > > is #ifdefed out, too. >> > > > >> > > > Signed-off-by: Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxxxx> >> > > > --- >> > > > Hello, >> > > > >> > > > I'm unsure about getting rid of the flush_dcache_range. If powerpc needs >> > > > a flush ARM probably does, too, no? >> > > > If so, what it the right thing to do? Implement flush_dcache_range for >> > > > ARM (just wrapping flush_dcache_page?)? >> > > As Russell seem to be OK with the #ifdef, can you please take this >> > > patch? >> > >> > Ick, no. >> >> I never said I was OK with the #ifdef... > Ah, right, sorry. > >> > Come on, we don't have ifdefs in .c files for a reason, surely there is >> > a better fix for this some other way? >> >> I suggested ways to fix it, which apparantly got ignored. To repeat myself, >> what I said was: >> >> "Well, the folk introducing it should have added it to cachetlb.txt so >> that other folk know what the intentions of it are. At the moment it >> seems to be an unofficial extension with unknown semantics. Maybe the >> PPC folk can clear it up and fix other arches if they wish to make it >> an official arch cachetlb extension." > So what should we do? The fsl_udc_core driver currently fails to build > because it uses flush_dcache_range unconditionally. So the obvious ways > to fix it are: > > 1) define flush_dcache_range > a) in arch/arm > b) in the driver > 2) make the driver not use flush_dcache_range > a) #ifdef > b) revert 09ba0de (and probably some commits that depend on it) > c) use a different function to flush the cache I see no reason why a dma_map_*() function couldn't be used here? This is preventing the driver from being built. And the _fsl_readl stuffs, which was really introduced by PPC guys, yet it can be made generic enough I believe. The real requirement is really for a single kernel binary to run on different LE/BE configurations, which will hurt performance a bit and is normally not true on the i.MX SoCs, so that can be made as a config option in my POV, but not necessary #ifdef CONFIG_PPC32, maybe some better name PS: why PPC32 is using io_*() API instead of readl/writel(), ISTR PPC32 doesn't have a separate IO space. -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
