On Fri, Feb 03, 2017 at 10:20:29AM +0800, Hanjun Guo wrote:
> On 01/10/2017 08:00 PM, Lorenzo Pieralisi wrote:
> >Commit 618f535a6062 ("ACPI/IORT: Add single mapping function")
> >introduced a function (iort_node_get_id()) to retrieve ids for IORT
> >named components.
> >
> >The iort_node_get_id() takes an index as input to refer to a specific
> >mapping entry in the named component IORT node mapping array.
> >
> >For a mapping entry at a given index, iort_node_get_id() should return
> >the id value (through the id_out function parameter) and the IORT node
> >output_reference (through function return value) the given mapping entry
> >refers to.
> >
> >Technically output_reference values may differ for different map
> >entries, (see diagram below - mapped id values may refer to different eg
> >IORT SMMU nodes; the kernel may not be able to handle different
> >output_reference values for a given named component but the IORT kernel
> >layer should still report the IORT mappings as reported by firmware) but
> >current code in iort_node_get_id() fails to use the index function
> >parameter to return the correct output_reference value (ie it always
> >returns the output_reference value of the first entry in the mapping
> >array whilst using the index correctly to retrieve the id value from the
> >respective entry).
> >
> > |----------------------|
> > | named component |
> > |----------------------|
> > | map entry[0] |
> > |----------------------|
> > | id value |
> > | output_reference----------------> eg SMMU 1
> > |----------------------|
> > | map entry[1] |
> > |----------------------|
> > | id value |
> > | output_reference----------------> eg SMMU 2
> > |----------------------|
> > .
> > .
> > .
> > |----------------------|
> > | map entry[N] |
> > |----------------------|
> > | id value |
> > | output_reference----------------> eg SMMU 1
> > |----------------------|
> >
> >Consequently the iort_node_get_id() function always returns the IORT
> >node pointed at by the output_reference value of the first named
> >component mapping array entry, irrespective of the index parameter,
> >which is a bug.
> >
> >Update the map array entry pointer computation in iort_node_get_id() to
> >take into account the index value, fixing the issue.
> >
> >Fixes: 618f535a6062 ("ACPI/IORT: Add single mapping function")
> >Reported-by: Hanjun Guo <hanjun.guo@xxxxxxxxxx>
> >Reviewed-by: Hanjun Guo <hanjun.guo@xxxxxxxxxx>
> >Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx>
> >Cc: Hanjun Guo <hanjun.guo@xxxxxxxxxx>
> >Cc: Sinan Kaya <okaya@xxxxxxxxxxxxxx>
> >Cc: Tomasz Nowicki <tn@xxxxxxxxxxxx>
> >Cc: Nate Watterson <nwatters@xxxxxxxxxxxxxx>
> >Cc: "Rafael J. Wysocki" <rjw@xxxxxxxxxxxxx>
> >---
> >v1 -> v2:
> > - Updated/improved commit log
> > - Added review tags
>
> Forgot to mention that I tested this patch on Hisilicon
> D03,
>
> Tested-by: Hanjun Guo <hanjun.guo@xxxxxxxxxx>
>
> BTW, Lorenzo, Rafael, since it's a bugfix, can this be merged into
> 4.10-rc7?
Yes, I thought Rafael picked it up already (I can't see it in
patchwork any longer).
This one from Dan:
https://patchwork.kernel.org/patch/9521003/
should get in -rc7 too, we should have both fixes in before v4.10
is released.
Rafael can you send them both for -rc7 please ?
Thanks,
Lorenzo
--
To unsubscribe from this list: send the line "unsubscribe linux-acpi" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
