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by kadamski
Thu Jul 19, 2012 7:49 am
Forum: Raspbian
Topic: ALSA on Raspbian
Replies: 167
Views: 168574

Re: ALSA on Raspbian

Ok, so this thread is quite helpful to understand what has to be done. It's still not enough for me to know how to do this but at least I now get the context. So there is "ack" callback that is called after read/write operation to the buffer, which should use appl_ptr to know how much data was writt...
by kadamski
Thu Jul 19, 2012 7:16 am
Forum: Raspbian
Topic: ALSA on Raspbian
Replies: 167
Views: 168574

Re: ALSA on Raspbian

Yes, USB cards can handle MMAP. I believe they do so by using some intermediate buffer that is mmaped and then copied in chunks after userspace finishes writing to it. There is not too much documentation about that, only found this to mention it. I believe, current approach is the first case, while ...
by kadamski
Wed Jul 18, 2012 8:32 pm
Forum: Raspbian
Topic: ALSA on Raspbian
Replies: 167
Views: 168574

Re: ALSA on Raspbian

That sounds interesting. So we want to add mmap support to alsa driver: https://github.com/raspberrypi/linux/blob/rpi-patches/sound/arm/bcm2835-pcm.c Having mmap support would be great not only for plughw but also for things like jackd, dmix etc. I know you can add MMAP flags to the snd_pcm_hardwar...
by kadamski
Wed Jul 18, 2012 5:38 pm
Forum: General discussion
Topic: feedback on usage
Replies: 4
Views: 1014

Re: feedback on usage

Need 1 or 2 screw holes for easy mounting There is not enough space for that. It was considered but was not possible. Align the USB with RJ45 There is not enough space for that. Just look at the board. Add a cheap heat sink on top of ram It's not needed at all. There is no problem with heat on RPi ...
by kadamski
Wed Jul 18, 2012 6:38 am
Forum: General discussion
Topic: SD Card performance in R-Pi onboard slot
Replies: 289
Views: 157305

Re: SD Card performance in R-Pi onboard slot

Those errors means that you have updated kernel.img but havn't updated kernel modules in /lib/modules.
by kadamski
Tue Jul 17, 2012 7:50 pm
Forum: Raspbian
Topic: usb music + rpi-update == kernel dump
Replies: 1
Views: 898

Re: usb music + rpi-update == kernel dump

I don't think it's a raspbian related error, it's a generic kernel problem, I think. It's a problem with allocating memory (probably due to fragmentation) by kernel for running cp process. I
by kadamski
Tue Jul 17, 2012 7:22 pm
Forum: General discussion
Topic: SD Card performance in R-Pi onboard slot
Replies: 289
Views: 157305

Re: SD Card performance in R-Pi onboard slot

dom wrote: Are you sure? It looks to me like its only adding SDHCI_QUIRK_MULTIBLOCK_READ_ACMD12 when sync_after_dma is false.
Ahh, you're right. I'm an idiot.
by kadamski
Tue Jul 17, 2012 7:03 pm
Forum: Raspbian
Topic: raspberry pi foundation raspbian image
Replies: 151
Views: 42397

Re: raspberry pi foundation raspbian image

dom wrote: I get that too. I couple of people have told me it is harmless. I only get them during boot - not seen them subsequently.
I get that quite often (like, in 70% of cases) when copying files to/from /boot/. Not seeing them in any other cases. I wonder if it's because boot is vfat maybe?
by kadamski
Tue Jul 17, 2012 5:21 pm
Forum: Raspbian
Topic: ALSA on Raspbian
Replies: 167
Views: 168574

Re: ALSA on Raspbian

Sorry to interrupt your thread but i have finally got plug plugin working on internal audio device. To make it working, I had to use mmap emulation ALSA plugin. Here's how I've set it up: pcm.mmap0 { type mmap_emul; slave { pcm "hw:0,0"; } } pcm.!default { type plug; slave { pcm mmap0; } } So it see...
by kadamski
Tue Jul 17, 2012 4:36 pm
Forum: General discussion
Topic: SD Card performance in R-Pi onboard slot
Replies: 289
Views: 157305

Re: SD Card performance in R-Pi onboard slot

Looking at that kernel patch, it seems that it's enabling SDHCI_QUIRK_MULTIBLOCK_READ_ACMD12 quirk no matter what is sync_after_dma value set to. Maybe this is why performance was degraded also with sync_after_dma turned on?
by kadamski
Tue Jul 17, 2012 4:23 pm
Forum: General discussion
Topic: Use initramfs?
Replies: 58
Views: 41948

Re: Use initramfs?

Using official kernel.img (this one: Linux pisces 3.1.9+ #168 PREEMPT Sat Jul 14 18:56:31 BST 2012 armv6l GNU/Linux) it actually work without boot_delay. Using my kernels, it does not in both compressed and uncopressed version. My kernel was compiled from raspberrypi-linux-178f598, using bcmrpi_defc...
by kadamski
Tue Jul 17, 2012 3:41 pm
Forum: General discussion
Topic: Use initramfs?
Replies: 58
Views: 41948

Re: Use initramfs?

Can you try boot_delay=1 (or 2). I don't think anything has changed with respect to overclocking, but it sounds like some sort of race condition that gets hit with faster sdram freq and avoided when loading the initramfs. boot_delay may be another way of avoiding it. Seems like you're right. boot_d...
by kadamski
Tue Jul 17, 2012 3:27 pm
Forum: Raspbian
Topic: I2C errors
Replies: 8
Views: 3617

Re: I2C errors

It may not me power issue. It can be a problem with mixing USB1.1 and USB2.0 devices. I heard of some problems with such configurations. So it has nothing to do with how the kernel was compiled, right? And BTW, you really don't have to recompile the kernel for it to work with raspbian. As I said, ke...
by kadamski
Tue Jul 17, 2012 3:21 pm
Forum: Raspbian
Topic: ALSA on Raspbian
Replies: 167
Views: 168574

Re: ALSA on Raspbian

I was finally able to test plug ALSA plugin on other soundcard. I was using some creative USB audio card (using snd_usb_audio module) and plughw does work as it should with this card. This means it's a driver problem. Some more investigation is needed. @bryankemp You said that you don't have problem...
by kadamski
Tue Jul 17, 2012 10:58 am
Forum: Raspbian
Topic: I2C errors
Replies: 8
Views: 3617

Re: I2C errors

Linux kernel does not use floating point. So what you mean by "softfloat" and "hardfloat" kernel?
by kadamski
Tue Jul 17, 2012 8:14 am
Forum: Raspbian
Topic: Torrent apps gives a kernel panic
Replies: 20
Views: 5815

Re: Torrent apps gives a kernel panic

https://github.com/raspberrypi/linux/issues Will be a better place to report a bug to.
by kadamski
Tue Jul 17, 2012 8:10 am
Forum: Raspbian
Topic: I2C errors
Replies: 8
Views: 3617

Re: I2C errors

Try using w-scan. It doesn't need initial configuration file and should just scan all available configurations. This can be longer, though.
by kadamski
Mon Jul 16, 2012 6:08 pm
Forum: Advanced users
Topic: mount Pi Sd card in USB
Replies: 12
Views: 42634

Re: mount Pi Sd card in USB

Are you sure your card reader works ok and you have the card properly inserted? It looks like your reader does not see the card (at least it looks the same if I don't insert the card)
by kadamski
Mon Jul 16, 2012 6:02 pm
Forum: General discussion
Topic: Kernel Panics - any way to auto reboot?
Replies: 19
Views: 8626

Re: Kernel Panics - any way to auto reboot?

The file extension doesn't matter to dd. It will produce the same file no matter what you name it. So of course you can use .img extension to make it clear what the file is by just it's name but it's not obligatory.
by kadamski
Mon Jul 16, 2012 5:56 pm
Forum: Raspbian
Topic: ALSA on Raspbian
Replies: 167
Views: 168574

Re: ALSA on Raspbian

But I need to know if using plughw with PCM that can not be handled by hw itself (on USB card) is going to work. It should as this is what plughw is for but for some reason it is not for RPi buildin sound chip.
by kadamski
Mon Jul 16, 2012 4:13 pm
Forum: Raspbian
Topic: ALSA on Raspbian
Replies: 167
Views: 168574

Re: ALSA on Raspbian

@lintweaker
Would you be so kind and test if there is the same plughw problem also on USB audio device? This could point me out if it's driver or userspace problem. To do this you would need to compile and run a simple C program i would provide.
by kadamski
Mon Jul 16, 2012 3:17 pm
Forum: General discussion
Topic: Easy GPIO Hardware & Software
Replies: 133
Views: 48507

Re: Easy GPIO Hardware & Software

Rumours are, that it's already part of "standard" RPi kernel:
https://github.com/raspberrypi/linux/co ... 0d06291d7b
by kadamski
Mon Jul 16, 2012 3:07 pm
Forum: Raspbian
Topic: ALSA on Raspbian
Replies: 167
Views: 168574

Re: ALSA on Raspbian

Did you try to turn this card off, wait for a minute, then on again? Normal reboot doesn't have to do the full power-cycle on the USB devices. I don't think reinstalling ALSA will help in any way.
by kadamski
Mon Jul 16, 2012 11:16 am
Forum: General discussion
Topic: Can I sell a product made with Raspberry Pi?
Replies: 2
Views: 17714

Re: Can I sell a product made with Raspberry Pi?

This subject was discussed couple times on the forums already. Here are some links:
http://www.raspberrypi.org/phpBB3//view ... 29&t=10644
http://www.raspberrypi.org/phpBB3/viewt ... =63&t=2490

I'm sure you can find some more using forums search (or better yet, using google).
by kadamski
Mon Jul 16, 2012 11:01 am
Forum: Debian
Topic: Updating modules after /boot update ?
Replies: 3
Views: 929

Re: Updating modules after /boot update ?

rpi-update should update kernel modules for you (so my suggestion is not relevant if you used rpi-update).. But you said, you updated boot files manually from github so I thought you where downloading them manually and placing them in /boot directory, not using rpi-update. Is that right? If so, then...

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