Messages in this thread | | | Date | Thu, 21 Sep 2006 22:30:35 +0400 | From | Sergey Vlasov <> | Subject | broken modules.alias entries for some USB devices |
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On Thu, 21 Sep 2006 16:54:24 +0200 iSteve wrote:
> I've got one more question, this time regarding modules.usbmap. > > -modules.usbmap: > ibmcam 0x000f 0x0545 0x8080 0x0002 0x0002 0x00 0x00 0x00 0x00 0x00 0x00 0x0 > ibmcam 0x000f 0x0545 0x8080 0x030a 0x030a 0x00 0x00 0x00 0x00 0x00 0x00 0x0 > ibmcam 0x000f 0x0545 0x8080 0x0301 0x0301 0x00 0x00 0x00 0x00 0x00 0x00 0x0 > ibmcam 0x000f 0x0545 0x8002 0x030a 0x030a 0x00 0x00 0x00 0x00 0x00 0x00 0x0 > ibmcam 0x000f 0x0545 0x800c 0x030a 0x030a 0x00 0x00 0x00 0x00 0x00 0x00 0x0 > ibmcam 0x000f 0x0545 0x800d 0x030a 0x030a 0x00 0x00 0x00 0x00 0x00 0x00 0x0 > -EOF > > -With corresponding aliases: > alias usb:v0545p8080d0002dc*dsc*dp*ic*isc*ip* ibmcam > alias usb:v0545p8080d030[10-9]dc*dsc*dp*ic*isc*ip* ibmcam > alias usb:v0545p8080d0301dc*dsc*dp*ic*isc*ip* ibmcam > alias usb:v0545p8002d030[10-9]dc*dsc*dp*ic*isc*ip* ibmcam > alias usb:v0545p800Cd030[10-9]dc*dsc*dp*ic*isc*ip* ibmcam > alias usb:v0545p800Dd030[10-9]dc*dsc*dp*ic*isc*ip* ibmcam > -EOF > > I absolutely do not understand the d030[10-9], where fields bcdDevice_lo and > bcdDevice_hi are 0x030a...
This surely looks like a bug.
> Looking at drivers/usb/core/usb.c, it'd seem that the MODALIAS sent upon device > event doesn't have anything like this -- it would have "[...]d030A[...]". So I > wonder, how it got generated?
scripts/mod/file2alias.c generates these lines from the ID tables.
> -The relevant items in ibmcam.c: > static struct usb_device_id id_table[] = { > { USB_DEVICE_VER(IBMCAM_VENDOR_ID, IBMCAM_PRODUCT_ID, 0x0002, 0x0002) }, > { USB_DEVICE_VER(IBMCAM_VENDOR_ID, IBMCAM_PRODUCT_ID, 0x030a, 0x030a) }, > { USB_DEVICE_VER(IBMCAM_VENDOR_ID, IBMCAM_PRODUCT_ID, 0x0301, 0x0301) }, > { USB_DEVICE_VER(IBMCAM_VENDOR_ID, NETCAM_PRODUCT_ID, 0x030a, 0x030a) }, > { USB_DEVICE_VER(IBMCAM_VENDOR_ID, VEO_800C_PRODUCT_ID, 0x030a, 0x030a) }, > { USB_DEVICE_VER(IBMCAM_VENDOR_ID, VEO_800D_PRODUCT_ID, 0x030a, 0x030a) },
The problem is that the bcdDevice field is supposed to be BCD - i.e., its hex representation should contain only decimal digits 0..9. Therefore a proper USB device cannot have bcdDevice == 0x030a. Apparently some ibmcam devices violate this and use the bcdDevice field as if it was binary.
> { } > }; > -EOF > > -And the resulting alias part of modinfo: > alias: usb:v0545p8080d0002dc*dsc*dp*ic*isc*ip* > alias: usb:v0545p8080d030[10-9]dc*dsc*dp*ic*isc*ip* > alias: usb:v0545p8080d0301dc*dsc*dp*ic*isc*ip* > alias: usb:v0545p8002d030[10-9]dc*dsc*dp*ic*isc*ip* > alias: usb:v0545p800Cd030[10-9]dc*dsc*dp*ic*isc*ip* > alias: usb:v0545p800Dd030[10-9]dc*dsc*dp*ic*isc*ip*
The code in scripts/mod/file2alias.c assumes that the bcdDevice_lo and bcdDevice_hi field contain proper BCD data. Seems that, thanks to buggy hardware, this assumption is incorrect, and the code needs to support any hex numbers there. [unhandled content-type:application/pgp-signature] | |