Re: Question regarding MUSB and dynamic fifo sizing

[Peter Barada <peterb@logicpd.com>]

On Mon, 2009-08-10 at 20:02 +0300, Felipe Balbi wrote:
> Hi,
> 
> On Mon, Aug 10, 2009 at 01:00:07PM -0400, Peter Barada wrote:
> > Actually, not quite.  I noticed that twl4030_vbus_work only sets Vbus,
> > never clears it. 
> > With that change and the driver configured for OTG mode (I had it host
> > when I tested), it doesn't enumerate.
> > 
> > I added code to decipher the link state, and on startup I now see:
> > 
> > Jan  1 00:00:13 OMAP-35x user.debug kernel: twl4030_usb twl4030_usb:
> > HW_CONDITIONS 0x72/114; link 1 (None)
> > 
> > Then when I load the driver:
> > 
> > Jan  1 00:01:30 OMAP-35x user.debug kernel: twl4030_usb twl4030_usb:
> > HW_CONDITIONS 0xf2/242; link 2 (Vbus)
> > Jan  1 00:01:30 OMAP-35x user.debug kernel: twl4030_usb twl4030_usb:
> > HW_CONDITIONS 0x72/114; link 1 (None)
> > 
> > And when I plug in the OTG adapter/thumbdrive:
> > 
> > Jan  1 00:02:24 OMAP-35x user.debug kernel: twl4030_usb twl4030_usb:
> > HW_CONDITIONS 0x76/118; link 3 (ID)
> > 
> > and Vbus goes to +5V 30mS after ID grounds, and stays at 5V for only
> > 30mS then goes back to ground.  Pulling out and reinserting repeast the
> > cycle.
> > 
> > During this total time, only two interrupts occur ont he MUSB
> > controller.  It looks like the connect interrupt is not occuring.
> > 
> > I'm adding more code to track the interrupts for both the twl4030-usb
> > and musb_hdrc so I can understand better what's happening (and more
> > importantly what's not).
> 
> good you reported :-)
> 
> I was about to send a version to linux-usb. Let's see what's going on:
> 
> on you setup:
> 
> # echo 3 > /sys/modules/musb_hdrc/parameters/debug
> # echo 9 > /proc/sysrq-trigger
> 
> this will give you more verbose output of what musb sees. BTW, it's odd
> you get a VBUS link irq when there shouldn't be any unless you have the
> board attached to pc at that time.

Nothing's attached to the OTG port at that time.  W/nothing plugged in
from powerup, The log first shows:

Jan  1 12:26:13 OMAP-35x user.debug kernel: twl4030_usb twl4030_usb:
HW_CONDITIONS 0x72/114; link 1 (None)

I rebuild with musb_debug=3 to get messages from the module on startup,
and nothing plugges in from powerup, loading the module comes back with:

OMAP-35x# modprobe musb_hdrc
musb_hdrc: version 6.0, pio, host, debug=3
HS USB OTG: revision 0x33, sysconfig 0x2010, sysstatus 0x1, intrfsel
0x1, simenable  0x0
musb_hdrc: ConfigData=0xde (UTMI-8, dyn FIFOs, bulk combine (X), bulk
split (X), HB-ISO Rx, HB-ISO Tx, SoftConn)
musb_hdrc: MHDRC RTL version 1.400
musb_hdrc: setup fifo_mode 4
musb_hdrc: 28/31 max ep, 16384/16384 memory
musb_hdrc: hw_ep 0shared, max 64
musb_hdrc: hw_ep 1tx, max 512
musb_hdrc: hw_ep 1rx, max 512
musb_hdrc: hw_ep 2tx, max 512
musb_hdrc: hw_ep 2rx, max 512
musb_hdrc: hw_ep 3tx, max 512
musb_hdrc: hw_ep 3rx, max 512
musb_hdrc: hw_ep 4tx, max 512
musb_hdrc: hw_ep 4rx, max 512
musb_hdrc: hw_ep 5tx, max 512
musb_hdrc: hw_ep 5rx, max 512
musb_hdrc: hw_ep 6tx, max 512
musb_hdrc: hw_ep 6rx, max 512
musb_hdrc: hw_ep 7tx, max 512
musb_hdrc: hw_ep 7rx, max 512
musb_hdrc: hw_ep 8tx, max 512
musb_hdrc: hw_ep 8rx, max 512
musb_hdrc: hw_ep 9tx, max 512
musb_hdrc: hw_ep 9rx, max 512
musb_hdrc: hw_ep 10tx, max 256
musb_hdrc: hw_ep 10rx, max 64
musb_hdrc: hw_ep 11tx, max 256
musb_hdrc: hw_ep 11rx, max 64
musb_hdrc: hw_ep 12tx, max 256
musb_hdrc: hw_ep 12rx, max 64
musb_hdrc: hw_ep 13shared, max 4096
musb_hdrc: hw_ep 14shared, max 1024
musb_hdrc: hw_ep 15shared, max 1024
musb_hdrc: USB Host mode controller at d80ab000 using PIO, IRQ 92
musb_hdrc musb_hdrc: MUSB HDRC host driver
musb_hdrc musb_hdrc: new USB bus registered, assigned bus number 1
usb usb1: configuration #1 chosen from 1 choice
hub 1-0:1.0: USB hub found
hub 1-0:1.0: 1 port detected
musb_start 883: <== devctl 80
usb usb1: New USB device found, idVendor=1d6b, idProduct=0002
usb usb1: New USB device strings: Mfr=3, Product=2, SerialNumber=1
usb usb1: Product: MUSB HDRC host driver
usb usb1: Manufacturer: Linux 2.6.28-rc8-omap1-05704-gf6ea2bb-dirty
musb-hcd
usb usb1: SerialNumber: musb_hdrc
musb_init_controller 2057: HOST mode, status 0, devctl 81 B
twl4030_usb twl4030_usb: HW_CONDITIONS 0xf2/242; link 2 (Vbus)
OMAP-35x# musb_stage2_irq 812: SUSPEND (b_idle) devctl 91 power e0
twl4030_usb twl4030_usb: HW_CONDITIONS 0x72/114; link 1 (None)

Looking at the schematics, outside of a 4.7uF between Vbus and ground,
nothing else is connected to the OTG D+, D-, ID, or Vbus except the
connector...

1) With the twl4030 triggering Vbus, the MUSB must think its a
peripheral, and then goes into suspend - why would the twl4030 think its
getting Vbus supplied to it?

-- 
Peter Barada <peterb@logicpd.com>
Logic Product Development, Inc.