On Wed, Mar 16, 2011 at 08:23:11AM -0700, Greg KH wrote: > On Wed, Mar 16, 2011 at 03:48:53PM +0100, Sven Köhler wrote: > > Hi, > > > > I'm not sure, whether you consider this is an issue. However, the device > > I have (Lego NXT in SAM-BA mode, lsusb shows it as 03eb:6124 Atmel Corp. > > at91sam SAMBA bootloader) is supported by both cdc_acm and sam_ba kernel > > modules, which leads to unpredictable behaviour. > > (Tested 2.6.38 - same issue in 2.6.37) > > I think Johan is the best one to answer this, as he submitted the sam-ba > driver. > > Johan, any thoughts on the below info? > > > > > > If I plug the device in, the following happens if cdc_acm is already loaded: > > > usb 4-1: new full speed USB device using uhci_hcd and address 3 > > > cdc_acm 4-1:1.0: This device cannot do calls on its own. It is not a modem. > > > cdc_acm 4-1:1.0: ttyACM0: USB ACM device > > > usbcore: registered new interface driver cdc_acm > > > cdc_acm: v0.26:USB Abstract Control Model driver for USB modems and ISDN adapters > > > USB Serial support registered for sam-ba > > > usbcore: registered new interface driver sam-ba > > > sam_ba: v1.0: Atmel SAM Boot Assistant (SAM-BA) driver > > > > After unloading both cdc_acm and sam_ba, the following happends: > > > usb 4-1: new full speed USB device using uhci_hcd and address 4 > > > USB Serial support registered for sam-ba > > > sam-ba 4-1:1.1: sam-ba converter detected > > > usb 4-1: sam-ba converter now attached to ttyUSB0 > > > usbcore: registered new interface driver sam-ba > > > sam_ba: v1.0: Atmel SAM Boot Assistant (SAM-BA) driver > > > cdc_acm 4-1:1.0: This device cannot do calls on its own. It is not a modem. > > > cdc_acm: probe of 4-1:1.0 failed with error -16 > > > usbcore: registered new interface driver cdc_acm > > > cdc_acm: v0.26:USB Abstract Control Model driver for USB modems and ISDN adapters > > > > As you can see, the device is recognized by cdc_acm as well as sam_ba. > > Depending on which module is loaded, the device is either claimed by > > cdc_acm or sam_ba. The device name may be either ttyACM* or ttyUSB* Tradionally the generic usb-serial driver was used to access the SAM-BA boot application; this is documented in the Atmel tools, which also expect the device to show up as a ttyUSBx node. Due to changes in the generic driver the tools stopped working from 2.6.32 and a dedicated driver was later written (sam-ba). A couple of weeks after the sam-ba driver was submitted, however, 5b239f0aebd4dd6f85b13decf5e18e86e35d57f0 (USB: cdc-acm: Add pseudo modem without AT command capabilities) was submitted, which causes cdc_acm to bind to these devices as well. > > I have no clue, whether there are Atmel SAM-BA implementations that do > > not support the cdc profile. > > > > I'm not sure, whether the device should be blacklisted in cdc_acm in > > favor of sam_ba. However, I have the feeling that if sam_ba is actually > > installed, sam_ba should claim the device even if cdc_acm is already loaded. > > > > Last time I tested, the device was working fine with cdc_acm, though. I just connected a at91sam9260-ek board and can confirm that the samba tools do seem to work with the cdc-acm driver, although it does require a ttyUSBx symlink for the device to be recognised by the user-space tools (latest v2.10). I'm not sure about how to proceed with this. What do you say, Greg? Thanks, Johan -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
