[PATCH v1] cmd: acpi: Print revisions in hex format

[Andy Shevchenko]

On Wed, Sep 09, 2020 at 09:15:22AM +0200, Wolfgang Wallner wrote:
> -----"Andy Shevchenko" <andy.shevchenko at gmail.com> schrieb: -----
> > Betreff: Re: [PATCH v1] cmd: acpi: Print revisions in hex format
> > On Tue, Sep 08, 2020 at 05:32:08PM +0200, Wolfgang Wallner wrote:
> > > -----"Andy Shevchenko" <andy.shevchenko at gmail.com> schrieb: -----
> > > > On Tue, Sep 8, 2020 at 5:58 PM Wolfgang Wallner
> > > > <wolfgang.wallner at br-automation.com> wrote:
> > > > > -----"Andy Shevchenko" <andriy.shevchenko at linux.intel.com> schrieb: -----

...

> > > > > Related to "acpi list":
> > > > > During my recent ACPI debugging I found it very useful to have the checksum
> > > > > printed for each table with "acpi list". Would there be interest to have that
> > > > > upstream? If so I would send a patch.
> > > > 
> > > > Can you elaborate what was the problem that checksum helped?
> > > 
> > > Sure. I saw two strange things with the ACPI checksums:
> > > 
> > > 1) The DSDT length included uninitialized bytes from alignment. This is
> > > described in the following link:
> > > 
> > >    https://lists.denx.de/pipermail/u-boot/2020-September/425378.html
> > >    
> > > This was the actual bug I was looking for.
> > >    
> > > 2) acpi_create_spcr() is missing a memset(). The other acpi_create_xxxx()
> > > functions perform a memset on their structure, acpi_create_spcr() does not
> > > and as a result the contents of this table are party uninitialized.
> > > 
> > > I plan to send a patch for both of them.
> > 
> > I'm not sure I understood how checksum pointed to uninitialized data?
> 
> After adding the checksums to "acpi list" I realized that the checksums for
> DSDT and SPCR where different after every reset. Looking at the code each
> turned out to be somehow related to uninitialized memory.

I see. I would rather to have it as a separate (sub-)command. But I leave this
to Simon.

-- 
With Best Regards,
Andy Shevchenko