On Wed, Mar 16, 2011 at 07:28:25PM +0100, Johan Hovold wrote: > 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? If the sam-ba driver is not needed, we can just remove it. The symlink issue should be fixable in the userspace tools to just get it to look for the different port (it should never have hard-coded ttyUSB0 anyway, what if it was on ttyUSB3?). So, want me to delete it? thanks, greg k-h -- 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
