Hi,
during my testing on jdolecek-ncq branch, I found that when I attach the ATAPI device via a port multiplier, the device is never actually detected. The behaviour I see is that atapibus is detected on the port, but not the actual device cd1, like this:
...
atabus10 at siisata0 channel 0
...
atabus10: SATA port multiplier, 15 ports
atabus10: vendor 0x197b, product 0x0325, revision 1.1, level 0
atabus10 PMP port 0: device present, speed: 1.5Gb/s
atabus10 PMP port 1: device present, speed: 3.0Gb/s
atabus10 PMP port 2: device present, speed: 3.0Gb/s
atabus10 PMP port 3: device present, speed: 1.5Gb/s
...
atapibus0 at atabus10: 1 targets
...
It gets detected like this when attached directly:
...
atabus11 at siisata0 channel 1
...
atapibus0 at atabus11: 1 targets
cd1 at atapibus0 drive 0: <HL-DT-STDVDRW GA32N, K0ZA5FI1046, KC08> cdrom removable
cd1: drive supports PIO mode 4, DMA mode 2, Ultra-DMA mode 5 (Ultra/100)
cd1(siisata0:1:0): using PIO mode 4, DMA mode 2, Ultra-DMA mode 5 (Ultra/100) (using DMA)
This behaviour is same on kernel from HEAD sources and my ncq branch.
Is ATAPI behind a PMP supposed to work, or does this depend on the particular card maybe? I thought one of user cases for port multiplier is to attach all the 'slow' devices through it, to save direct ports for fast disks.
Could this be maybe driver issue? Do ATAPI devices connected via PMP work e.g. on ahcisata(4)?
This particular port multiplier has issue with port detection (satapmp claims it has 15 ports when it has only 5), so it's entirely possible it could have problem with ATAPI pass-through also.
Jaromir