Messages in this thread | | | Date | Mon, 08 Jul 2013 19:52:50 +0200 | From | Takashi Iwai <> | Subject | Re: dell_rbu: Select CONFIG_FW_LOADER_USER_HELPER explicitly |
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At Mon, 8 Jul 2013 09:49:33 -0700, Greg KH wrote: > > On Mon, Jul 08, 2013 at 11:05:20AM +0200, Takashi Iwai wrote: > > The reason is that dell_rbu driver requires it. Without the kconfig > > option, this driver won't work at all. So, it's a right fix for > > dell_rbu. > > > > AFAIK, the consensus in the kernel side is that this too long fw > > loading time is basically a regression of user-space (udev or > > whatever). There is no change in the kernel behavior. The problem > > must exist even with the older kernels. > > > > But, looking at the development, we can't expect that udev will be > > fixed soon, and this breakage persists already way too long. Maybe a > > better solution is to kill the fallback to udev for normal f/w loading > > (i.e. for distro kernels). > > I thought udev was already fixed for this issue, so why would a "modern" > distro need to worry about this?
Hm, I expected Dave is using the udev "modern" enough. If it's about an old udev behavior, we don't have to care so much...
> > The patch below is an untested quick hack. It adds a new Kconfig and > > a new function request_firmware_via_user_helper(). Distro kernels may > > set CONFIG_FW_LOADER_USER_HELPER_FALLBACK=n for avoiding 60 seconds > > stall for non-existing firmware file access -- as distributions know > > that the firmware files should be placed in the right path. > > > > Thoughts? > > There's no way we can just fix up the driver instead of doing this in > the firmware core?
The problem is that this non-udev-hotplug firmware loading mechanism was introduced exactly for this driver. Thus, we can't change the driver (thus ABI) without breaking user-space.
Though, there are only two users of this interface. So, once when the user-space side is fixed, we can easily fix the kernel side, too, e.g. rewrite these drivers without abusing firmware interface.
Takashi
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