Gilles Chanteperdrix wrote: > Philippe Gerum wrote: >> Gilles Chanteperdrix wrote: >>> Michael Galea wrote: >>>> I wonder if someone can suggest an approach to the following problem. >>>> >>>> We need to use xenomai to manage devices on the mii bus. The mii >>>> bus has PHYs managed by linux. What is the best way of providing >>>> access to both linux and xenomai? >>>> >>>> I know that before xenomai "loads", I can simply access the mii bus >>>> from linux. But after xenomai loads, is the right answer to make >>>> the linux function that reads the phy migrate into the xenomai >>>> domain and contend for the bus there? >>> What protects this access to the bus, is this a mutex or a spinlock ? >>> If a spinlock, then simply make it an ipipe_spinlock, it will provide >>> mutual exclusion between all domains. >>> >> >> It's a spinlock_bh, but you can't tell actually, since there is a >> callback >> mechanism to perform the actual read depending on the bus implementation. >> Additionally, genphy_read may trigger an update from the link status >> and so on. >> I'm afraid this kind of sport may well resemble playing Russian >> roulette with a >> fully loaded gun. This said, if all executed code paths can be >> identified and >> fixed, why not (having fun). > > I was talking about the actual implementation by the hardware driver, > not the generic part. This probably depends on the driver. > >
The drivers don't do much, except IRQ handling. Most of them route their requests to the generic PHY layer, therefore a parallel implementation would be needed. Still, concurrency on the bus would not be solved. -- Philippe. _______________________________________________ Xenomai-help mailing list Xenomai-help@gna.org https://mail.gna.org/listinfo/xenomai-help
