Donald M Burns wrote:
> I've just downloaded and installed ALSA 0.9.2 complete with OSS emulation.
> I'm using an Addonics Sound Vision SV550 which is based on the Yamaha
> YMF724F chip, and running Red Hat 7.3.
>
> Whilest all is OK with the PCM and OPL3 bits the MIDI record function does not
> work. [...]
> I had a similar problem with old OSS driver (ymfpci.c) and tracked it down to
> the fact that only ISA interrupts for the midi were supported by the driver.
> This means that the driver is OK  for midi on motherboard mounted chips but
> cannot work with PCI cards as there is no way to route an ISA interrupt across
> the PCI bus. I came up with a simple patch which fixed it in the end.
>
> I was wondering if we had the same problem with ALSA driver.

snd_card_ymfpci_probe() contains the following code:

        ...
        // this bit is for legacy mpu irqs
        // legacy_ctrl |= 0x10; /* MPU401 irq enable */
        legacy_ctrl2 |= 1 << 15; /* IMOD */
        ...
        if ((err = snd_mpu401_uart_new(card, 0, MPU401_HW_YMFPCI,
                                       mpu_port[dev], 0,
                                       pci->irq, 0, &chip->rawmidi)) < 0) {
                printk(KERN_WARNING "ymfpci: cannot initialize MPU401 at 0x%lx, 
skipping...\n", mpu_port[dev]);
                mpu_port[dev] = 0;
                // only for legacy mpu irqs
                // legacy_ctrl &= ~0x10; /* disable MPU401 irq */
                // pci_write_config_word(pci, PCIR_DSXG_LEGACY, legacy_ctrl);
        }
        ...

This code apparently assumes that the MIDI port uses the PCI interrupt
line. I don't have a ymfpci card, so I don't know if this assumption is
correct, or what the "IMOD" bit does.


HTH
Clemens




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