RE: EXT SENDER - Re: IMX FEC model- modification in interrupts

[Olek, Adam]

Thank you for your answer, we understand that compatibility with all Linux 
versions is a priority for you.
We have small hope that this email will help other QEMU users in struggling 
with QNX on QEMU.

Regards,
Adam Olek

-----Original Message-----
From: Peter Maydell [mailto:peter.maydell@linaro.org] 
Sent: Thursday, March 11, 2021 8:07 PM
To: Olek, Adam <adam.olek@aptiv.com>
Cc: qemu-devel@nongnu.org
Subject: EXT SENDER - Re: IMX FEC model- modification in interrupts

On Thu, 11 Mar 2021 at 09:27, Olek, Adam <adam.olek@aptiv.com> wrote:
> We have tried to up and running QNX 7.0 on QEMU 5.2.0 Sabrelite model. The 
> QNX reach the prompt and was responsive to user command.
> However, starting the network caused a QNX freeze. After debugging the 
> problem at QNX and QEMU sites we end up with a solution which requires a 
> slight QEMU source code modification.
>
> It seem that the hw/net/imx_fec.c is source of the problem. To fix the issue 
> we changed the condition in line 442 from:
>
> if (s->regs[ENET_EIR] & s->regs[ENET_EIMR] &
>      (ENET_INT_MAC | ENET_INT_TS_TIMER)) {
>
> to:
>
> if (s->regs[ENET_EIR] & s->regs[ENET_EIMR] & ENET_INT_TS_TIMER) {

> Can anyone take a closer look at this condition and confirm that this 
> modification make sense and it hasn’t negative impact on anything else?

There is a massive comment immediately before these lines of code which 
explains why it is doing what it is doing, what would stop working, and what 
other functionality in QEMU needs to be implemented in order for the hack to be 
removed...

thanks
-- PMM