Takashi Iwai wrote: > At Fri, 25 Apr 2008 09:06:19 +0200, > Pavel Hofman wrote: >> Takashi Iwai wrote: >>>> I do not know the reason for MPU401_INFO_NO_ACK. You removed it from the >>>> original patch, but without it I always get the input/output error. >>> Ah, thanks, I overlooked it. >>> Fixed now. >> Takashi, thanks, but the patch I sent you sets MPU401_INFO_INPUT and >> MPU401_INFO_OUTPUT flags too. They enable the actual input/output >> methods in mpu401_uart.c. > > They aren't needed if you create full-duplex streams. > Could you check whether the latest code still causes any errors? The code works fine on standard kernel. But in the RT kernel of Ubuntu 7.10 (2.6.22-14-rt, 1000HZ compared to 250HZ of the -generic kernel), MIDI interrupts get thrown continuously, hogging CPU with the IRQXX "process". When playing 44.1kHz audio with buffer size of 32768, snd_vt1724_interrupt is called every 185ms. With the buffer size of 4096, it is every 23ms. So far so good. But when I try to output some midi, the routine gets called every 24us (i.e. 1000 times faster). Comparing the time difference between my several debug printk's in snd_vt1724_interrupt (approx. 5us between each printk record a few lines of code apart) and between each call of the method (24us), I thought there would be a loop somewhere in the interrupt handler calling code. But /proc/interrupts really shows over 40k interrupts a second for ICE1724. Changing the watermarks up to 0x1f makes no difference. Masking the MIDI interrupts works, snd_vt1724_interrupt is called only during VT1724_IRQ_MTPCM interrupts, with the MIDI status bits MPU_TX/MPU_RX set when reading/writing with amidi. My HW: ancient AMD Duron 900MHz. The interrupt flood occurs no matter whether the MIDI input is connected to my MIDI keyboard or not. Thanks a lot to anyone for suggestions. Pavel. _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
