From mboxrd@z Thu Jan 1 00:00:00 1970 From: Denis Vlasenko Date: Fri, 28 Jul 2006 10:47:11 +0000 Subject: Re: Sound problems with snd_hda on x86_64 Message-Id: <200607281247.11986.vda.linux@googlemail.com> List-Id: References: <200607281216.25214.vda.linux@googlemail.com> In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Takashi Iwai Cc: Andi Kleen , PeiSen Hou , linux-sound@vger.kernel.org, alsa-devel@alsa-project.org, linux-kernel@vger.kernel.org On Friday 28 July 2006 12:29, Takashi Iwai wrote: > > Which is, in turn, is caused by this code: > > > > --- linux-2.6.17.6.org/sound/core/pcm_compat.c 2006-07-15 21:00:43.000000000 +0200 > > +++ linux-2.6.17.6.src/sound/core/pcm_compat.c 2006-07-28 00:35:10.000000000 +0200 > > @@ -478,6 +478,8 @@ static long snd_pcm_ioctl_compat(struct > > * mmap of PCM status/control records because of the size > > * incompatibility. > > */ > > +printk("substream->no_mmap_ctrl = 1 in %s:%s line %d\n", __FILE__, __FUNCTION__, __LINE__); > > +dump_stack(); > > substream->no_mmap_ctrl = 1; > > > > switch (cmd) { > > > > It's puzzling. Even a 486 processor, can do 64-bit operations (using cmpxchg8) > > on memory-mapped areas, why does code disallows mmap for 64-bit CPUs but allows > > for 32-bit ones? > > On the contrary, the driver disallows mmap for 32bit task on 64bit > architecture. This is because the size of the mapped record is > different between 32bit and 64bit architectures, so it cannot be > shared. Why artsd attempts mmap at all then? Why it thinks that /dev/snd/pcmC0D0p is mmap-able when it is not? > BTW, with the recent version of alsa-lib, you no longer need artsd > unless you want a network transparent. Disable it on kde control > center. This is good. -- vda