Messages in this thread | | | From | Linus Walleij <> | Date | Tue, 9 Jan 2018 15:47:37 +0100 | Subject | Re: [PATCH] ARM: realview: remove eb-mp clcd IRQ |
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On Mon, Jan 8, 2018 at 5:31 PM, Robin Murphy <robin.murphy@arm.com> wrote: > On 21/12/17 22:08, Linus Walleij wrote:
>> I do think the reference design has a character LCD, and I >> do think it has an interrupt, it's just undocumented so >> someone with this board would have to test it manually >> to figure out which line it is. Whoever uses this design >> will get to it if ever. > > FWIW the EB baseboard is *physically* the same regardless of the CPU, it's > just flashed with a Core-Tile-specific FPGA bitstream.
Aha I always wondered how that works :)
> I've just tried > firing up an 11MPCore one, and indeed the character LCD does light up with > the kernel version. I can't convince the recalcitrant beast to actually get > to userspace, though, so I can't confirm what the interrupt's deal is.
Yeah the driver survives fine without an IRQ too so it just works ...
> The baseboard manual (DUI0303E) says it's interrupt 22 on the board-level > secondary GICs, and since neither the CT11MP nor its corresponding FPGA > (AN152) mention any alternate routing direct to the Core Tile GIC, I'd guess > it probably still is. On the other hand, though, it also says this: > > "... However this interrupt signal is reserved for future use and you > must use a polling routine instead of an interrupt service routine." > > So maybe it's appropriate to just remove the interrupt everywhere :/
Hm I don't think there will be future releases of these EB boards anytime soon, so I suspect we could just add it.
But as it works fine without IRQ we can just leave it as well.
Yours, Linus Walleij
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