diff --git a/Documentation/admin-guide/perf/imx-ddr.rst b/Documentation/admin-guide/perf/imx-ddr.rst index 5438dd3a0c42..59fab27f62a1 100644 --- a/Documentation/admin-guide/perf/imx-ddr.rst +++ b/Documentation/admin-guide/perf/imx-ddr.rst @@ -2,6 +2,8 @@ Freescale i.MX8 DDR Performance Monitoring Unit (PMU) ===================================================== +1. PMU in DRC (DDR Controller) + There are no performance counters inside the DRAM controller, so performance signals are brought out to the edge of the controller where a set of 4 x 32 bit counters is implemented. This is controlled by the CSV modes programed in counter @@ -97,3 +99,15 @@ un-supported, and value 1 for supported. automatically. So that users do not need specify axi_channel if want to monitor data channel from DDR transactions, since data channel is more meaningful. + +2. PMU in DB (DRAM Block) + + There is a performance counter function included in the DB which allows + statistics to be captured for the various ports. The module is similar to + the one deployed in the DRC but has the ability to select one of the incoming + ports to gather statistics on it. The AXI IDs used is the one seen at one PORT. + + .. code-block:: bash + + perf stat -a -e imx8_db0/axid-read,axi_mask=0xMMMM,axi_id=0xDDDD,axi_port=0xPP,axi_channel=0xH/ cmd + perf stat -a -e imx8_db0/axid-write,axi_mask=0xMMMM,axi_id=0xDDDD,axi_port=0xPP,axi_channel=0xH/ cmd