[v2 PATCH] net: fec_mxc: add DM_FLAG_ACTIVE_DMA flag for FEC network driver

[Fabio Estevam]

On Sun, Dec 22, 2024 at 11:41 PM Meng Li <Meng.Li at windriver.com> wrote:
>
> From: Meng Li <meng.li at windriver.com>
>
> When FEC network card works as the prime one in u-boot, and is in
> active status, kernel might crash during booting up stage, especially
> working with grub. Because the DMA of FEC is still in active status, and
> copy data into memory if there is network data received. In this case, if
> kernel allocated a part of memory that has overlay with the memory
> used by DMA, kernel memory may be destroyed and cause kernel crashes.
> Because before kernel boots up really, u-boot dm_remove_devices_flags()
> can call the remove callback of FEC driver with DM_FLAG_ACTIVE_DMA
> flag. In fecmxc_remove(), phy power is disabled, so there is no data
> received. In this way, it makes sure that there is no DMA action, so
> that avoid kernel crashing occurs.
>
> Signed-off-by: Meng Li <Meng.Li at windriver.com>

Applied to u-boot-imx/next, thanks.