David Miller wrote:
From: Daniel Hellstrom <daniel@xxxxxxxxxxx>
Date: Wed, 16 Mar 2011 16:54:24 +0100
The AMBA Plug&Play information supports only 1 IRQ per AMBA device,
a device node in linux is an AMBA core which consists of 3 devices
(AHB Master, AHB Slave and APB Slave in any combination). The IRQ
information is really the first IRQ of a device, the Plug&Play does
not tell how many IRQs are actually present on a device so the
interrupt property of a device can impossibly tell how many IRQs
each device has, it must be up to the driver to probe the hardware
in a device-specific way simply know how many IRQs are present.
Using Virtual IRQs does not work for such devices, because VIRQ+1
is not REAL_IRQ+1. Thus, the LEON architecture needs real IRQs or
map virtual IRQs 1:1 to real IRQs.
This patch changes the VIRQ allocation to try the real IRQ if not
already taken.
LEON IRQ Controller is edge triggered, not masking or acking is
needed in the normal case, handle_simple_irq handler can be used
for that.
Signed-off-by: Daniel Hellstrom <daniel@xxxxxxxxxxx>
As I stated in another email I am absolutely and completely against
this change.
Just because you only store one interrupt in the firmware device node,
it does not mean that you cannot store multiple interrupts in the
internal device node structure we build. And then have the drivers
use that.
Yes, I agree with you that this is the best solution. However, the
hardware simply does not support that. That would require the bootloader
to have one driver per core and that the bootloader must be modified
each time a user of LEON or gaisler adds a new core.
I have made another patch that creates all 0..15 IRQs on startup instead
in leon_kernel.c. It will ensure linearity within that range, and
patching of irq_32.c is not needed. Perhaps that is more acceptable?
Regards,
Daniel
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