Re: [irda-users] [RFT] Revised SigmaTel 4200 driver

[Stephen H. <she...@os...>]

> For me the significant gain in rx-path was observed after setting 
> MODE_FASTRX. Wrt. the polling - I think we could avoid the heuristics 
> there by using an usb interrupt in transfer - something like 4 msec 
> interval should be sufficient - at least for SIR. However this would mean 
> to abandon the nice concept of your thread doing only simple synch usb 
> calls. So it's probably not worth the effort unless it would turn out 
> there is a real win.

This hardware doesn't have the capability for receive interrupt transfers.
It only reports two endpoints: bulk in and bulk out without the interrupt
attribute. So your idea of a interrupt transfer probably wouldn't work.

Bus 001 Device 002: ID 066f:4200 SigmaTel, Inc. STIr4200 IrDA Bridge
Device Descriptor:
  bLength                18
  bDescriptorType         1
  bcdUSB               1.10
  bDeviceClass          255 Vendor Specific Class
  bDeviceSubClass         1 
  bDeviceProtocol         0 
  bMaxPacketSize0        64
  idVendor           0x066f SigmaTel, Inc.
  idProduct          0x4200 STIr4200 IrDA Bridge
  bcdDevice            0.08
  iManufacturer           1  Sigmatel Inc 
  iProduct                2  IrDA/USB Bridge
  iSerial                 0 
  bNumConfigurations      1
  Configuration Descriptor:
    bLength                 9
    bDescriptorType         2
    wTotalLength           32
    bNumInterfaces          1
    bConfigurationValue     1
    iConfiguration         17
    bmAttributes         0x80
    MaxPower              440mA
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        0
      bAlternateSetting       0
      bNumEndpoints           2
      bInterfaceClass         0 Interface
      bInterfaceSubClass      0 
      bInterfaceProtocol      0 
      iInterface              0 
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x01  EP 1 OUT
        bmAttributes            2
          Transfer Type            Bulk
          Synch Type               none
        wMaxPacketSize         64
        bInterval               0
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x82  EP 2 IN
        bmAttributes            2
          Transfer Type            Bulk
          Synch Type               none
        wMaxPacketSize         64
        bInterval               0
  Language IDs: (length=4)
     0409 English(US)