On Wed, 23 Oct 2013, Paulo Zanoni <przanoni@xxxxxxxxx> wrote: > 2013/10/23 Ben Widawsky <ben@xxxxxxxxxxxx>: >> On Mon, Oct 21, 2013 at 11:56:09AM -0200, Paulo Zanoni wrote: >>> From: Paulo Zanoni <paulo.r.zanoni@xxxxxxxxx> >>> >>> The audio driver uses the power well provided by our driver, so on >>> Haswell we can't "rmmod i915" if we don't "rmmod snd_hda_intel" first. >>> >>> The problem with removing snd_hda_intel is that we also need to kill >>> its users. On the specific machine I tested, the only user seem to be >>> alsactl, but on other machines this may change. IMHO we should leave >>> the "kill user space" step to whoever is running the script, but >>> Daniel asked me to put it here so we have a better chance of Just >>> Working on QA's machines. >>> >>> Signed-off-by: Paulo Zanoni <paulo.r.zanoni@xxxxxxxxx> >>> --- >>> tests/module_reload | 6 ++++++ >>> 1 file changed, 6 insertions(+) >>> >>> diff --git a/tests/module_reload b/tests/module_reload >>> index 3d8cb85..c1fd395 100755 >>> --- a/tests/module_reload >>> +++ b/tests/module_reload >>> @@ -18,6 +18,10 @@ if ! echo 0 > /sys/class/vtconsole/vtcon1/bind ; then >>> exit 77 >>> fi >>> >>> +# The sound driver uses our power well >>> +pkill alsactl >>> +rmmod snd_hda_intel &> /dev/null >>> + >>> #ignore errors in ips - gen5 only >>> rmmod intel_ips &> /dev/null >>> rmmod i915 >>> @@ -38,6 +42,8 @@ fi >>> modprobe i915 >>> echo 1 > /sys/class/vtconsole/vtcon1/bind >>> >>> +modprobe snd_hda_intel >>> + >>> # try to run something >>> $SOURCE_DIR/gem_exec_nop > /dev/null && echo "module successfully loaded again" >>> >> >> I don't really pretend to understand how module dependencies are >> calculated. However, I would think the dependency should be *somewhere* >> and so modprobe -r i915 should work. > > It's the opposite: "modprobe -r i915" will remove drm.ko, > drm_kms_helper, i2c-algo-bit and video, but won't remove snd_hda_intel > (and if you don't remove it first, it will complain that i915.ko is > still in use). > >> >> Don't read that as a nak. Rather, a wtf is with the existing stuff? > > I think the dependency is magically tracked by depmod when it sees the > Audio driver uses a symbol exported by i915.ko. But a "modinfo > snd_hda_intel" doesn't show i915.ko on the "depends" section, which is > strange. I'm also not an expert on this area... This is because snd_hda_intel does not depend on i915, to make it possible to use snd_hda_intel without i915. Which makes sense. Instead, it uses symbol_request() to be able to call a couple of i915 functions when available. I don't know if there's a way to check this runtime dependency from userspace. But obviously you can't remove i915 while snd_hda_intel holds function pointers to i915. (In fact, intel_ips is the same.) BR, Jani. -- Jani Nikula, Intel Open Source Technology Center _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/intel-gfx
