[pvrusb2] HVR-1950 not being found at boot (along side a pvrusb2 2900 device)

[Mike Isely]

On Tue, 2 Jun 2009, Roger wrote:

> The pvrusb2 driver is *only* picking-up the "pvrusb2 2900 device" and
> not the "hvr-1950".  (Both are plugged into the same USB host
> controller.)
> 
> At boot, only the "pvrusb2 2900" is being found and does work with
> mythtv/mplayer.
> 
> The following two lines within /var/log/messages, especially the second
> line, are ominously absent from boot:
> 
> Jun  2 13:09:37  usb 1-4: new high speed USB device using ehci_hcd and
> address 10
> Jun  2 13:09:37  usb 1-4: New USB device found, idVendor=2040,
> idProduct=7501
> 
> 
> Searching the entire past boot log for "usb 1-4" or "hcd and address 10"
> seems absent as well until the device is replugged-in.
> 
> Looks like pvrusb2 is either failing to detect both devices, or the host
> controller is only reporting one at 
> boot.

Uh, so how did you have this working before?  What changed?

> 
> 
> (BTW, I have removed i2c_scan as a module option and for the past
> several boots I've noticed this activity.)

The i2c_scan option has nothing to do with this.


> 
> Using in-kernel pvrusb2 driver.
> 
> # uname -a
> Linux localhost2.local 2.6.29-gentoo-r4Y #9 SMP PREEMPT Tue Jun 2
> 03:38:16 AKDT 2009 i686 Pentium III (Coppermine) GenuineIntel GNU/Linux
> 

The mechanism in Linux which associates a newly-plugged-in device with 
its driver is outside of the driver itself.  Said another way, the 
pvrusb2 driver does not itself "detect" the hardware but rather the 
kernel does the detection and then another mechanism (udev, IIRC) 
figures out which driver should be associated with it.  The driver is 
then called with a handle to the hardware device - at the point the 
driver is entered the detection is already done.

If the pvrusb2 driver is not responding when you plug in an HVR-1950, 
then something is preventing the association from working.  When the 
pvrusb2 driver is compiled one of the elements it exports to the kernel 
is a table of USB ids (vendor+product ids) which tell the Linux system 
what the driver can handle.  Odds are that the table is incomplete.

A more interesting question is how that can happen.  And for that I have 
a very simple question for you: Obviously you had this working before, 
so WHAT DID YOU CHANGE?

  -Mike

-- 

Mike Isely
isely @ isely (dot) net
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