[REGRESSION] firmware: dmi_scan: add SBMIOS entry and DMI tables
From: Paul Menzel
Date: Mon Mar 28 2016 - 05:28:49 EST
Dear Ivan, dear Jeann,
There is an unwanted regression due to commitÂd7f96f97 (firmware:
dmi_scan: add SBMIOS entry and DMI tables).
Since Linux kernel 4.2 the utility `cbmem`, used to access information
stored in memory, from the coreboot project  does not work anymore
on a lot of systems as reported in corebootâs issue tracker as ticket
Failed to mmap /dev/mem: Resource temporarily unavailable
Aaron Durbin analyzed on the coreboot mailing list :
> > 3) Why is that range set as uncached-minus?ÂÂWould write-back work?
> Please see this thread:
> The actual issue stems from
> which maintains a persistent mapping of smbios tables. It uses
> dmi_remap() which is '#define dmi_remap ioremap' which is where the
> uncached-minus PAT entry comes from. It should be using the same
> mechanism asÂÂthe ACPI table mappings which uses ioremap_cache().
Itâd be great, if the commit could be reverted, or the code be changed
in a way that `cbmem` still works.
If I should report this issue somewhere else, please tell me too, and
Iâll do my best to follow up there.
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