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....@linaro.org> Reviewed-by: Hanjun Guo <hanjun....@linaro.org> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieral...@arm.com> Cc: Hanjun Guo <hanjun....@linaro.org> Cc: Sinan Kaya <ok...@codeaurora.org> Cc: Tomasz Nowicki <t...@semihalf.com> Cc: Nate Watterson <nwatt...@codeaurora.org> Cc: "Rafael J. Wysocki" <r...@rjwysocki.net> --- 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....@linaro.org> BTW, Lorenzo, Rafael, since it's a bugfix, can this be merged into 4.10-rc7? Thanks Hanjun
