From bb6f7de21d4c3f53999758bc3ee1396acf92ec7a Mon Sep 17 00:00:00 2001 From: Suzuki K Poulose Date: Fri, 12 Apr 2024 15:27:02 +0100 Subject: [PATCH] coresight: etm4x: Fix access to resource selector registers [ Upstream commit d6fc00d0f640d6010b51054aa8b0fd191177dbc9 ] Resource selector pair 0 is always implemented and reserved. We must not touch it, even during save/restore for CPU Idle. Rest of the driver is well behaved. Fix the offending ones. Reported-by: Yabin Cui Fixes: f188b5e76aae ("coresight: etm4x: Save/restore state across CPU low power states") Signed-off-by: Suzuki K Poulose Tested-by: Yabin Cui Reviewed-by: Mike Leach Link: https://lore.kernel.org/r/20240412142702.2882478-5-suzuki.poulose@arm.com Signed-off-by: Sasha Levin --- drivers/hwtracing/coresight/coresight-etm4x-core.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c index a409872c2571..840e4cccf8c4 100644 --- a/drivers/hwtracing/coresight/coresight-etm4x-core.c +++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c @@ -1720,7 +1720,8 @@ static int __etm4_cpu_save(struct etmv4_drvdata *drvdata) state->trccntvr[i] = etm4x_read32(csa, TRCCNTVRn(i)); } - for (i = 0; i < drvdata->nr_resource * 2; i++) + /* Resource selector pair 0 is reserved */ + for (i = 2; i < drvdata->nr_resource * 2; i++) state->trcrsctlr[i] = etm4x_read32(csa, TRCRSCTLRn(i)); for (i = 0; i < drvdata->nr_ss_cmp; i++) { @@ -1851,7 +1852,8 @@ static void __etm4_cpu_restore(struct etmv4_drvdata *drvdata) etm4x_relaxed_write32(csa, state->trccntvr[i], TRCCNTVRn(i)); } - for (i = 0; i < drvdata->nr_resource * 2; i++) + /* Resource selector pair 0 is reserved */ + for (i = 2; i < drvdata->nr_resource * 2; i++) etm4x_relaxed_write32(csa, state->trcrsctlr[i], TRCRSCTLRn(i)); for (i = 0; i < drvdata->nr_ss_cmp; i++) {