This is a note to let you know that I've just added the patch titled drivers/perf: thunderx2_pmu: Fix memory resource error handling to the 5.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: drivers-perf-thunderx2_pmu-fix-memory-resource-error.patch and it can be found in the queue-5.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 488107a300c73145e78f6c12fb1ef457fa531ff4 Author: Mark Salter <msalter@xxxxxxxxxx> Date: Tue Sep 15 16:41:10 2020 -0400 drivers/perf: thunderx2_pmu: Fix memory resource error handling [ Upstream commit 688494a407d1419a6b158c644b262c61cde39f48 ] In tx2_uncore_pmu_init_dev(), a call to acpi_dev_get_resources() is used to create a list _CRS resources which is searched for the device base address. There is an error check following this: if (!rentry->res) return NULL In no case, will rentry->res be NULL, so the test is useless. Even if the test worked, it comes before the resource list memory is freed. None of this really matters as long as the ACPI table has the memory resource. Let's clean it up so that it makes sense and will give a meaningful error should firmware leave out the memory resource. Fixes: 69c32972d593 ("drivers/perf: Add Cavium ThunderX2 SoC UNCORE PMU driver") Signed-off-by: Mark Salter <msalter@xxxxxxxxxx> Link: https://lore.kernel.org/r/20200915204110.326138-2-msalter@xxxxxxxxxx Signed-off-by: Will Deacon <will@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/perf/thunderx2_pmu.c b/drivers/perf/thunderx2_pmu.c index aac9823b0c6bb..e116815fa8092 100644 --- a/drivers/perf/thunderx2_pmu.c +++ b/drivers/perf/thunderx2_pmu.c @@ -805,14 +805,17 @@ static struct tx2_uncore_pmu *tx2_uncore_pmu_init_dev(struct device *dev, list_for_each_entry(rentry, &list, node) { if (resource_type(rentry->res) == IORESOURCE_MEM) { res = *rentry->res; + rentry = NULL; break; } } + acpi_dev_free_resource_list(&list); - if (!rentry->res) + if (rentry) { + dev_err(dev, "PMU type %d: Fail to find resource\n", type); return NULL; + } - acpi_dev_free_resource_list(&list); base = devm_ioremap_resource(dev, &res); if (IS_ERR(base)) { dev_err(dev, "PMU type %d: Fail to map resource\n", type);