Re: [PATCH v2 0/2] of: property: Add fw_devlink support for more props

From: Saravana Kannan
Date: Sun Jan 31 2021 - 16:21:23 EST


On Sun, Jan 31, 2021 at 8:38 AM Martin Kaiser <martin@xxxxxxxxx> wrote:
>
> Dear all,
>
> Thus wrote Saravana Kannan (saravanak@xxxxxxxxxx):
>
> > Sending again because I messed up the To/Cc for the coverletter.
>
> > This series combines two patches [1] [2] that'd conflict.
>
> > Greg,
>
> > Can you please pull this into driver-core-next?
>
> > -Saravana
>
> > [1] - https://lore.kernel.org/lkml/20210115210159.3090203-1-saravanak@xxxxxxxxxx/
> > [2] - https://lore.kernel.org/lkml/20201218210750.3455872-1-saravanak@xxxxxxxxxx/
>
> I'm running linux-next on my hardware which is based on the imx258
> chipset by Freescale/NXP.
>
> When those two patches appeared in linux-next, my system would not boot
> any more. It was stuck right after
>
> Uncompressing Linux... done, booting the kernel.
>
> Reverting the irq-patch made the system boot again. Still, a number of
> devices like usb or nand flash controller are not found any more.
> If I revert the gpio patch as well, all devices are available again.
>
> My system's device tree is based on arch/arm/boot/dts/imx25.dtsi with
> very few adaptations for my board.
>
> I tried to play around with the new parse_interrupts() function to
> figure out which device causes the boot failure. If I skip the following
> device, I can boot again:
>
> - return of_irq_find_parent(np);
> + np_ret = of_irq_find_parent(np);
> + if (!strcmp(np->full_name, "serial@50008000")) {
> + printk(KERN_ERR "skip serial@50008000\n");
> + return NULL;
> + }
> + return np_ret;
>
> This is uart4 of the imx258 chip, which I use as my serial console. The
> imx25.dtsi device tree seems ok, we find an interrupt parent. The
> problem must be in the code that processes the result of
> parse_interrupts().
>
> I tried to boot the unmodified code with qemu, simulating the imx25-pdk
> device. This wouldn't boot either.
>
> Does this ring any bells with anyone?

This series [1] has a high chance of fixing it for you if
CONFIG_MODULES is disabled in your set up. Can you give it a shot?

The real problem is that arch/arm/mach-imx/avic.c doesn't set the
OF_POPULATED flag for the "fsl,avic" node. fw_devlink uses this
information to know that this device node will never have a struct
device created for it. The proper way to do this for root IRQCHIP
nodes is to use IRQCHIP_DECLARE(). I Cc'ed you on a clean up patch for
IMX [2], can you please give [2] a shot *without* [1] and with
CONFIG_MODULES enabled? Things should boot properly with this
combination too.

Btw, for future reference, you can try enabling the logs in
device_links_check_suppliers() to see what devices are being blocked
on what supplier nodes.

[1] - https://lore.kernel.org/lkml/20210130040344.2807439-1-saravanak@xxxxxxxxxx/
[2] - https://lore.kernel.org/lkml/20210131205654.3379661-1-saravanak@xxxxxxxxxx/T/#u

Thanks,
Saravana