dmaengine: ARM pl080 misidentified as Samsung pl080s

Russell King - ARM Linux linux at arm.linux.org.uk
Thu Mar 24 08:16:47 PDT 2016


On Thu, Mar 24, 2016 at 11:56:51AM +0100, Johannes Stezenbach wrote:
> Hi,
> 
> commit da1b6c05b8b5bd ("dmaengine: PL08x: Add support for PL080S variant")
> added this hunk:
> 
>  static struct amba_id pl08x_ids[] = {
> +       /* Samsung PL080S variant */
> +       {
> +               .id     = 0x0a141080,
> +               .mask   = 0xffffffff,
> +               .data   = &vendor_pl080s,
> +       },
>         /* PL080 */
> 
> However, 0x0a141080 happens to be the ID of the
> ARM PL080, too:
> http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.ddi0196g/I54627.html
> 
> Since the PL080S has the configuration register at a different
> address the driver doesn't work for ARM PL080 anymore.

Vendors have got into serious trouble in the past over IDs claiming that
some other legal entity being the vendor.  A certain buggy ARM926 clone
comes to mind, and they were forced to respin their silicon as a result.
It sounds like Samsung have made the same idiotic mistake.  I suggest
reverting the offending commit.  This behaviour really isn't on.

-- 
RMK's Patch system: http://www.arm.linux.org.uk/developer/patches/
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