RE: [PATCH net] net: dsa: microchip: fix wrong register write when masking interrupt

From: Tristram.Ha
Date: Thu May 30 2024 - 19:18:03 EST


> Subject: Re: [PATCH net] net: dsa: microchip: fix wrong register write when masking
> interrupt
>
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> On Tue, 2024-05-28 at 14:35 -0700, Tristram.Ha@xxxxxxxxxxxxx wrote:
> > From: Tristram Ha <tristram.ha@xxxxxxxxxxxxx>
> >
> > The initial code used 32-bit register. After that it was changed to 0x1F
> > so it is no longer appropriate to use 32-bit write.
>
> IMHO the above sentence is too much unclear. It sort of implies that
> the currently used register is 8 bit wide because such register address
> can be represented with 8 bit - which in turn sounds weird or
> irrelevant.
>
> I guess some documentation describes register 0x1F, please rephrase the
> changelog accordingly.

I will clarify the comment.
Initially the REG_SW_PORT_INT_MASK__4 is defined as 0x001C in
ksz9477_reg.h and REG_PORT_INT_MASK is defined as 0x#01F. Because the
global and port interrupt handling is about the same new
REG_SW_PORT_INT_MASK__1 is defined as 0x1F in ksz_common.h. This works
as only the least significant bits have effect. As a result the 32-bit
write needs to be changed to 8-bit.