This is a note to let you know that I've just added the patch titled
coresight: etm4x: Fix access to resource selector registers
to the 6.9-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:
coresight-etm4x-fix-access-to-resource-selector-regi.patch
and it can be found in the queue-6.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 779130684e215853c254b39bd4e072f82c9228b8
Author: Suzuki K Poulose <suzuki.poulose@xxxxxxx>
Date: Fri Apr 12 15:27:02 2024 +0100
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 <yabinc@xxxxxxxxxx>
Fixes: f188b5e76aae ("coresight: etm4x: Save/restore state across CPU low power states")
Signed-off-by: Suzuki K Poulose <suzuki.poulose@xxxxxxx>
Tested-by: Yabin Cui <yabinc@xxxxxxxxxx>
Reviewed-by: Mike Leach <mike.leach@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20240412142702.2882478-5-suzuki.poulose@xxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c
index 8643b77e50f41..a0bdfabddbc68 100644
--- a/drivers/hwtracing/coresight/coresight-etm4x-core.c
+++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c
@@ -1758,7 +1758,8 @@ 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++) {
@@ -1889,7 +1890,8 @@ 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++) {
