RE: Can request_firmware be called from a platform_driver ?
|[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]|
-----Original Message----- From: Dave Hylands [mailto:dhylands@xxxxxxxxx] Sent: Wednesday, April 18, 2012 3:15 PM To: Holmes, Michael A (Mike) Cc: kernelnewbies@xxxxxxxxxxxxxxxxx Subject: Re: Can request_firmware be called from a platform_driver ? Hi Mike, On Wed, Apr 18, 2012 at 11:07 AM, Holmes, Michael A (Mike) <Mike.Holmes@xxxxxxx> wrote: > Hi > > I have a fully working system to which I want to add the request firmware > mechanism to an existing platform driver I have working. > > I instrumented mdev in busybox 1.5.1 and in firmware_class.c 2.6.35 so that > I could figure this out. > > What I see with firmware_request() is that the kernel makes the firmware > request and does not find any firmware and mdev sees nothing. > > However if I change my code to do request_firmare_nowait(), the entire > system comes up and about 30seconds in the timeout calls my kernel side > continue for request_firmare_nowait() and I DO now see my request handled by > mdev, however it is a REMOVE request not the ADD request. > > All this makes me think that platform drivers exist before the hotplug > mechanism is able to operate, is this true ? Well, request_firmware is ultimately serviced by a user-space process. So platform drivers compiled statically into the kernel get initialized long before user-space starts. Platform drivers compiled as modules will get the firmware loaded much more quickly after loading the module. >>>>>>>> Thanks Dave, Currently in make menuconfig I put '*' against it to compile it into the kernel, I made it an 'm' so that it is made as a module. For modules made outside the tree I call modprobe to load them, but I never made a module in the tree before, I don't know how to get its init called. When it was compiled in, I called the init from my machine init directly in my mach-lcp/arch.c via platform_device_register() Mike -- Dave Hylands Shuswap, BC, Canada http://www.davehylands.com _______________________________________________ Kernelnewbies mailing list Kernelnewbies@xxxxxxxxxxxxxxxxx http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
[Newbies FAQ] [Linux Kernel Development] [IETF Annouce] [Git] [Networking] [Security] [Bugtraq] [Photo] [Yosemite] [MIPS Linux] [ARM Linux] [Linux Security] [Linux Networking] [Linux RAID] [Linux SCSI] [Linux ACPI]