Re: [PATCH] drm/bochs: add edid present check

From: Gerd Hoffmann
Date: Wed Dec 19 2018 - 10:21:34 EST


Hi,

> You could probably have a comment here explaining the magic below
> (just like in the commit message to ease the task of understanding
> while reading the code why 2 of 8 bytes of the EDID header is checked
> and why it is all needed). Of course one can use git blame... Up to you

Makes sense.

> > + if (readb(bochs->mmio + 0) != 0x00 ||
> > + readb(bochs->mmio + 1) != 0xff)
>
> bochs->mmio is defined as "void __iomem   *mmio;". Can we please avoid
> void pointer arithmetic here?

Why is that a problem? gcc uses bytes when doing pointer arithmetic
with void pointers (even though it is undefined in the C standard),
and as far I know the linux kernel depends on that behavior anyway.

Also the driver already does it everywhere.

cheers,
Gerd