> On Apr 19, 2016, at 03:29 , John Syne <[email protected]> wrote: > > It was part of this discussion in which you participated. > > https://groups.google.com/forum/#!msg/beagleboard/TMGEWjBLsok/ALk4h_jrCwAJ
Ooof, months ago. I can barely remember what I did last week. ;-) In any case, I didn't put it together back then. This is the first time I've gotten a 4+ kernel to do everything I need (e.g. pruss, adc, and audio). It's still not all quite there, but I'm much farther along than I was. I may have also missed the follow-on posts on that thread. In any case, it doesn't seem to allow audio to be overlayed when enabled in the boot DTB. > Robert spoke about this on Jan 12, 2016: > > it's a big workaround hack, the bug seems to be in edma_probe: > > https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/drivers/dma/edma.c#n2118 > > On first load of the board *.dtb, edma_probe is called and all the 'active' > nodes get an edma slot, while the in-active nodes get disabled.. (power > savings? for am335x, every ip has it's own edma channel, but maybe some parts > need sharing?) > > So, next when we load an overlay, for uart0, uart1, uart2, spi0, spi1, > mcasp0, and mcasp1 the edma channel would be disabled, (they still load, but > every transfer fails when it switches from pio-dma spi=160 bytes) as we don't > re-call edma_probe to enable them*.. > > * that seems like the better fix. I think I understand what's going on. However, I'm not seeing the result of failed transfers. Audio actually works for me now. In any case, for my primary application, I can make a single comprehensive DTB to load at boot, so I should be able to get edma and audio, right? I'll try this after I sleep and wake up. Also, those discussions were for 4.1.x. Does all that still hold true for 4.4.x? Thanks, Rick > > > Regards, > John > > > > >> On Apr 19, 2016, at 2:41 AM, Rick Mann <[email protected]> wrote: >> >> The following .dtsi file: >> >> >> https://github.com/RobertCNelson/dtb-rebuilder/blob/4.4.x/src/arm/am33xx-overlay-edma-fix.dtsi >> >> causes the mcasp davinci audio driver to load during boot, >> and prevents overlays (like BB-BONE-AUDI-02) from setting >> audio parameters. The result is hardware configuration errors >> when trying to use ALSA commands: >> >>> Unable to set hw params for playback: Invalid argument >>> Setting of hwparams failed: Invalid argument >> >> That .dtsi file enables spi0/1, and mcasp0/1. By removing >> the mcasp0/1 entries, the BB-BONE-AUDI-02 overlay is able >> to enable mcasp while configuring it properly, and allowing >> the driver to work. >> >> It's not clear to me how that file is an eDMA fix, nor why >> it enables mcasp. >> >> Here's the thread on the alsa-devel list where we figured it >> out: >> >> http://mailman.alsa-project.org/pipermail/alsa-devel/2016-April/107061.html >> >> Is the best way to report this problem here on the list like >> this, or to open an issue on github/dtb-rebuilder? >> >> Note that this is all with kernel 4.4.7-bone-rt-r9. Not sure >> to how many other versions it applies. >> >> Thanks! >> >> -- >> Rick Mann >> [email protected] >> >> >> -- >> For more options, visit http://beagleboard.org/discuss >> --- >> You received this message because you are subscribed to the Google Groups >> "BeagleBoard" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected]. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/beagleboard/77DEEFDD-F2AC-494B-A8AC-6BC54F19EEC3%40latencyzero.com. >> For more options, visit https://groups.google.com/d/optout. > > -- > For more options, visit http://beagleboard.org/discuss > --- > You received this message because you are subscribed to the Google Groups > "BeagleBoard" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To view this discussion on the web visit > https://groups.google.com/d/msgid/beagleboard/55916E28-05ED-4C01-89A5-5C6D30741FA9%40gmail.com. > For more options, visit https://groups.google.com/d/optout. -- Rick Mann [email protected] -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/beagleboard/FB865EB5-76E4-434E-8217-BC9FB39E0E35%40latencyzero.com. For more options, visit https://groups.google.com/d/optout.
