On Thu, Jun 24, 2010 at 6:10 PM, Kanigeri, Hari <h-kanigeri2@xxxxxx> wrote: > Ohad, > >> mbox_configured is global and therefore does not support >> concurrent usage of multiple mailbox instances. > > -- Why do you say that it doesn't support concurrent usage of multiple mailbox instances ? If you take example of OMAP4, we have 2 mailbox instances, one talking to DSP and other to Ducati and they should be supported concurrently. Interesting. was this actually tested and found working ? AFAICT (I don't have OMAP4, this is just by looking at the code) this doesn't work: mbox_configured will prevent omap2_mbox_startup from being invoked more than once. This means that omap2_mbox_enable_irq(mbox, IRQ_RX) will only be called once too, which seems like a problem if you want to start receiving RX interrupts from both mbox instances at the same time. To fix that I guess we should decouple the RX interrupt enabling from the mbox startup function. I can write something, but I'd need your help to test it on OMAP4 :) > > If you remove the mbox_configured variable, then the mailbox module would shut down > once the first instance calls the omap_mbox_put function. Also interesting point. So you use mbox_configures as a reference counter to allow concurrent multiple senders to the same mbox instance. I will update the previous patch (that introduced the atomic_t reference counter) to reflect this use case, thanks! > > Thank you, > Best regards, > Hari > -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
