On Mon, Aug 01, 2016 at 02:26:04PM +0200, Daniel Wagner wrote: > On 07/31/2016 09:23 AM, Dmitry Torokhov wrote: > >On July 30, 2016 9:58:17 AM PDT, "Luis R. Rodriguez" <mcgrof@xxxxxxxxxx> wrote: > >>On Sat, Jul 30, 2016 at 02:42:41PM +0200, Arend van Spriel wrote: > >>>On 29-07-16 08:13, Daniel Wagner wrote: > >>>>On 07/28/2016 09:01 PM, Bjorn Andersson wrote: > >>>>>On Thu 28 Jul 11:33 PDT 2016, Dmitry Torokhov wrote: > > >>>+ Luis (again) ;-) > > That was not on purpose :) My attempt to keep the Cc list a bit > shorter was a failure. > > >>>>>>Do not quite like it... I'd rather asynchronous request give out > >>>>>>firmware status pointer that could be used later on. > >>> > >>>Excellent. Why not get rid of the callback function as well and have > >>>fw_loading_wait() return result (0 = firmware available, < 0 = fail). > >>>Just to confirm, you are proposing a new API function next to > >>>request_firmware_nowait(), right? > >> > >>If proposing new firmware_class patches please bounce / Cc me, I've > >>recently asked for me to be added to MAINTAINERS so I get these > >>e-mails as I'm working on a new flexible API which would allow us > >>to extend the firmware API without having to care about the old > >>stupid usermode helper at all. > > These patches here are a first attempt to clean up a bit of the code > around the completion API. As Dmitry correctly pointed out, it makes > more sense to go bit further and make the async loading a bit more > convenient for the drivers. > > >I am not sure why we started calling usermode helper "stupid". We > >only had to implement direct kernel firmware loading because udev/stsremd > >folks had "interesting" ideas how events should be handled; but having > >userspace to feed us data is not stupid. > > I was ignorant on all the nasty details around the firmware loading. > If I parse Luis' patches correctly they introduce an API which calls > kernel_read_file_from_path() asynchronously: > > sysdata_file_request_async(..., &cookie) > *coookie = async_schedule_domain(request_sysdata_file_work_func(), ..) > > request_sysdata_file_work_fun() > _sysdata_file_request() > fw_get_filesystem_firmware() > kernel_read_file_from_path() > > sysdata_synchronize_request(&cookie); > > Doesn't look like what your asking for. No, but its also a generic kernel read issue as I noted in my last reply. > >If we want to overhaul firmware loading support we need to figure > >out how to support case when a driver want to [asynchronously] request > >firmware/config/blob and the rest of the system is not ready. Even if we > >want kernel to do read/load the data we need userspace to tell kernel > >when firmware partition is available, until then the kernel should not > >fail the request. > > I gather from Luis' blog post and comments that he is on the quest > on removing userspace support completely. No, I explained in my last proposed documentation patch series that we cannot get rid of the usermode helper. Its not well understood why so I explained and documented why. Best we can do is compartamentalize its uses. The sysdata API's main goal rather is to provide a flexible API first, compartamentalizing the usermode helper was secondary. But now it seems I may just also add devm support too to help simplify code further. What Dmitry notes is an existential issue with kernel_read_file_from_path() and we need a common solution for it. > Maybe this attempt here could be a step before. Step 1 would be > changing request_firmware_nowait() to request_firmware_async so > drivers don't have to come up with their own sync primitives, e.g. > > cookie = request_firmware_async() > fw_load_wait(cookie) That's one of the features already part of async mechanism of the sysdata API :) Luis -- To unsubscribe from this list: send the line "unsubscribe linux-kselftest" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
