Re: [PATCHv4 1/4] arm64: dts: qcom: sdm845: Add Coresight support

From: Suzuki K Poulose
Date: Thu Jan 24 2019 - 06:19:58 EST


Hi Sai,

On 23/01/2019 12:11, Sai Prakash Ranjan wrote:
Hi Suzuki,

On 1/23/2019 1:42 AM, Suzuki K Poulose wrote:
Hi Sai,

On 01/22/2019 04:48 PM, Sai Prakash Ranjan wrote:
Hi Suzuki,

[..]

SDM845 has 4 Kryo 385 Gold (ARM A75) + 4 Kryo 385 Silver (ARM A55),
so the PID values should be same for 4 ETMs atleast. But here one
pid value(001bb803) is same for 6 ETMs and other one for 2
ETMs(001bb802) which seems odd and hence the doubt if these pids
are even valid ones.

Have you checked other SoCs with A55 for the ETM PID ? The drivers
usually only care about PID0[7-0], PID1[7-0], PID2[3-0] and ignores
the other fields that may change over revisions of the core. So, in your
case the ETM ID could be treated as 0xbb802 and 0xbb803.


Very sorry to have mislead you here. I checked again today on SDM845 and
as you said 4 ETMs based on A75 has 0xbb803 and other 4 ETMs based on
A55 has 0Xbb803. I wrongly mentioned it as 6 and 2.

[ 6.688809] resname=etm@7040000 pid = 0x1bb803
[ 6.694957]
[ 6.694957] resname=etm@7140000 pid = 0x1bb803
[ 6.701135]
[ 6.701135] resname=etm@7240000 pid = 0x1bb803
[ 6.707256]
[ 6.707256] resname=etm@7340000 pid = 0x1bb803
[ 6.713454]
[ 6.713454] resname=etm@7440000 pid = 0x1bb802
[ 6.719621]
[ 6.719621] resname=etm@7540000 pid = 0x1bb802
[ 6.725814]
[ 6.725814] resname=etm@7640000 pid = 0x1bb802
[ 6.731971]
[ 6.731971] resname=etm@7740000 pid = 0x1bb802

So is it ok to add these to table as below in etm4x driver with the
following comment since these do not exactly match A75 and A55 PIDs
which you provided? Or any other way you prefer?

@@ -1079,6 +1079,10 @@ static const struct amba_id etm4_ids[] = {
ETM4x_AMBA_ID(0x000bb95a), /* Cortex-A72 */
ETM4x_AMBA_ID(0x000bb959), /* Cortex-A73 */
ETM4x_AMBA_ID(0x000bb9da), /* Cortex-A35 */
+ ETM4x_AMBA_ID(0x000f0211), /* Qualcomm Kryo */
+ ETM4x_AMBA_ID(0x000f0205), /* Qualcomm Kryo */
+ ETM4x_AMBA_ID(0x000bb803), /* Qualcomm Kryo 385
Cortex-A75 */
+ ETM4x_AMBA_ID(0x000bb802), /* Qualcomm Kryo 385
Cortex-A55 */
{},

That looks fine with me. But as Mathieu said, this needs to be a separate
patch. But before all that please could you provide me the PIDR4 value for
the Kryo A75 and A55 please ?

Kind regards
Suzuki