On Wed, Feb 17, 2010 at 03:32:45PM +0100, Michal Marek wrote: > On 12.2.2010 16:30, Alan Stern wrote: > > On Fri, 12 Feb 2010, Gadiyar, Anand wrote: > > > >>>>> I guess you did _not_ enable CONFIG_PM_RUNTIME, right? > >>>>> > >>>>> pm_wq is only defined when CONFIG_PM_RUNTIME is enabled. > >>>>> > >>>>> 15 #ifdef CONFIG_PM_RUNTIME > >>>>> 16 > >>>>> 17 extern struct workqueue_struct *pm_wq; > >>>> > >>>> Right, I had CONFIG_PM_RUNTIME disabled. Enabling it allowed the > >>>> compile to go through. > >>>> > >>>> Does that compile failure still needs to be fixed. I'm guessing > >>>> not everyone will build with this option enabled? > >>>> > >>> Well, looking at gregkh-07-usb-2.6.33-rc7.patch, I noticed following > >>> hunk of patch: > >>> > >>> diff -Naur -X linux-2.6.33-rc7-tty/Documentation/dontdiff linux-2.6.33-rc7-tty/drivers/usb/core/Kconfig linux-2.6.33-rc7-usb/drivers/usb/core/Kconfig > >>> --- linux-2.6.33-rc7-tty/drivers/usb/core/Kconfig 2009-09-09 15:13:59.000000000 -0700 > >>> +++ linux-2.6.33-rc7-usb/drivers/usb/core/Kconfig 2010-02-09 13:21:32.000000000 -0800 > >>> @@ -91,8 +91,8 @@ > >>> If you are unsure about this, say N here. > >>> > >>> config USB_SUSPEND > >>> - bool "USB selective suspend/resume and wakeup" > >>> - depends on USB && PM > >>> + bool "USB runtime power management (suspend/resume and wakeup)" > >>> + depends on USB && PM_RUNTIME > >>> help > >>> If you say Y here, you can use driver calls or the sysfs > >>> "power/level" file to suspend or resume individual USB > >>> > >>> This patch is saying, USB_SUSPEND is depends on PM_RUNTIME, in your > >>> case, USB_SUSPEND is enabled, but PM_RUNTIME is disabled, this is a > >>> little bit strange, I guess you have manually edited .config instead > >>> of running the command `make menuconfig`. I am afraid this might cause > >>> some dependency problem. > >> > >> Nope. I did `make ARCH=arm omap_3430sdp_defconfig`, and this generated > >> the .config. Wouldn't the dependencies be taken care of by this? > >> > >> (omap_3430sdp_defconfig has CONFIG_USB_SUSPEND=y and CONFIG_PM_RUNTIME > >> not set, since the defconfig is old. But wouldn't CONFIG_USB_SUSPEND > >> get turned off in this case?) > > > > I would expect it to get turned off. This sounds like a bug in the > > kernel build system. Adding the linux-kbuild mailing list to the CC:. > > The problem is a few lines below > > config USB_OTG > bool > depends on USB && EXPERIMENTAL > select USB_SUSPEND > ^^^^^^^^^^^^^^^^^^ > default n > > This triggers a know bug of the select statement > (Documentation/kbuild/kconfig-language.txt): > > select should be used with care. select will force > a symbol to a value without visiting the dependencies. > By abusing select you are able to select a symbol FOO even > if FOO depends on BAR that is not set. > In general use select only for non-visible symbols > (no prompts anywhere) and for symbols with no dependencies. > That will limit the usefulness but on the other hand avoid > the illegal configurations all over. > kconfig should one day warn about such things. > > Vegard Nossum is going to work on replacing the current kconfig > dependency solver with something smarter during this year's GSoC, so > there is light at the end of the tunnel. In the meantime, you can change > the logic from "select USB_SUSPEND" to "depends on USB_SUSPEND". This > will force one to first set USB_SUSPEND manually, but will avoid the > build error. A patch to do this would probably be best so we don't run into it again. thanks, greg k-h -- To unsubscribe from this list: send the line "unsubscribe linux-kbuild" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
