[PATCH] coresight: etm4x: Fix accesses to TRCSEQRSTEVR and TRCSEQSTR

[Junhao He]

The TRCSEQRSTEVR and TRCSEQSTR register is not implemented if the
TRCIDR5.NUMSEQSTATE == 0. Skip accessing the register in such cases.

Signed-off-by: Junhao He <hejunhao3 at huawei.com>
---
 .../hwtracing/coresight/coresight-etm4x-core.c | 18 ++++++++++++------
 1 file changed, 12 insertions(+), 6 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c
index 80fefaba58ee..c7a65d1524fc 100644
--- a/drivers/hwtracing/coresight/coresight-etm4x-core.c
+++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c
@@ -424,8 +424,10 @@ static int etm4_enable_hw(struct etmv4_drvdata *drvdata)
 		etm4x_relaxed_write32(csa, config->vipcssctlr, TRCVIPCSSCTLR);
 	for (i = 0; i < drvdata->nrseqstate - 1; i++)
 		etm4x_relaxed_write32(csa, config->seq_ctrl[i], TRCSEQEVRn(i));
-	etm4x_relaxed_write32(csa, config->seq_rst, TRCSEQRSTEVR);
-	etm4x_relaxed_write32(csa, config->seq_state, TRCSEQSTR);
+	if (drvdata->nrseqstate) {
+		etm4x_relaxed_write32(csa, config->seq_rst, TRCSEQRSTEVR);
+		etm4x_relaxed_write32(csa, config->seq_state, TRCSEQSTR);
+	}
 	etm4x_relaxed_write32(csa, config->ext_inp, TRCEXTINSELR);
 	for (i = 0; i < drvdata->nr_cntr; i++) {
 		etm4x_relaxed_write32(csa, config->cntrldvr[i], TRCCNTRLDVRn(i));
@@ -1631,8 +1633,10 @@ static int __etm4_cpu_save(struct etmv4_drvdata *drvdata)
 	for (i = 0; i < drvdata->nrseqstate - 1; i++)
 		state->trcseqevr[i] = etm4x_read32(csa, TRCSEQEVRn(i));
 
-	state->trcseqrstevr = etm4x_read32(csa, TRCSEQRSTEVR);
-	state->trcseqstr = etm4x_read32(csa, TRCSEQSTR);
+	if (drvdata->nrseqstate) {
+		state->trcseqrstevr = etm4x_read32(csa, TRCSEQRSTEVR);
+		state->trcseqstr = etm4x_read32(csa, TRCSEQSTR);
+	}
 	state->trcextinselr = etm4x_read32(csa, TRCEXTINSELR);
 
 	for (i = 0; i < drvdata->nr_cntr; i++) {
@@ -1760,8 +1764,10 @@ static void __etm4_cpu_restore(struct etmv4_drvdata *drvdata)
 	for (i = 0; i < drvdata->nrseqstate - 1; i++)
 		etm4x_relaxed_write32(csa, state->trcseqevr[i], TRCSEQEVRn(i));
 
-	etm4x_relaxed_write32(csa, state->trcseqrstevr, TRCSEQRSTEVR);
-	etm4x_relaxed_write32(csa, state->trcseqstr, TRCSEQSTR);
+	if (drvdata->nrseqstate) {
+		etm4x_relaxed_write32(csa, state->trcseqrstevr, TRCSEQRSTEVR);
+		etm4x_relaxed_write32(csa, state->trcseqstr, TRCSEQSTR);
+	}
 	etm4x_relaxed_write32(csa, state->trcextinselr, TRCEXTINSELR);
 
 	for (i = 0; i < drvdata->nr_cntr; i++) {
-- 
2.33.0