Hi, On 04/14/2017 20:25, Thomas Gleixner wrote: >> static int timer_irq; >> -module_param_named(irq, timer_irq, int, 0644); >> +module_param_hw_named(irq, timer_irq, int, irq, 0644); >> MODULE_PARM_DESC(irq, "Which IRQ to use for the clock source MFGPT ticks."); > > I'm not sure about this. AFAIR the parameter is required to work on > anything else than some arbitrary hardware which has it mapped to 0.
Parameter defaults to 0, which means: 1. autodetect (=keep IRQ BIOS has set up) 2. if that fails use CONFIG_CS5535_MFGPT_DEFAULT_IRQ (see drivers/misc/cs5535-mfgpt.c: cs5535_mfgpt_set_irq()) Autodetect works fine for our (ex-LiPPERT, now ADLINK) COTS boards: Linux auto-uses IRQ chosen in BIOS Setup. Wouldn't know about other companies, of course, but (2.) means parameter can be avoided via make menuconfig. On 04/15/2017 00:59, David Howells wrote: > Should it then be set through in-kernel platform initialisation > since the AMD Geode is an embedded chip? Don't know what each and every of our COTS customers is doing, but I'm not aware of anyone having written a platform driver. AFAIK many are running pretty standard distros, e.g. Debian. I happen to have booted Slackware with a vanilla kernel only a few hours ago. Cheers, Jens