Re: [EXT] Re: [PATCH RFC net-next 03/19] net: mvpp2: add CM3 SRAM memory map

From: Andrew Lunn
Date: Sun Jan 10 2021 - 12:44:33 EST


> > Should there be -EPROBE_DEFER handling in here somewhere? The SRAM is a
> > device, so it might not of been probed yet?
>

> No, firmware probed during bootloader boot and we can use SRAM. SRAM
> memory can be safely used.

A previous patch added:

+ CP11X_LABEL(cm3_sram): cm3@220000 {
+ compatible = "mmio-sram";
+ reg = <0x220000 0x800>;
+ #address-cells = <1>;
+ #size-cells = <1>;
+ ranges = <0 0x220000 0x800>;
+ };
+

So it looks like the SRAM is a device, in the linux driver model. And
there is a driver for this, driver/misc/sram.c. How do you know this
device has been probed before the Ethernet driver?

Andrew