[spi_host] Cleanup AscentLint errors, add waivers
- Remove an ASSERT that was being flagged as a null assertion.
- Request waivers for ascent lint rule CALC_NEXT_STATE for certain FSM state
transitions, in which the SPI_HOST FSM uses signals to ensure that idle state
transitions are performed consistently.
Signed-off-by: Martin Lueker-Boden <martin.lueker-boden@wdc.com>
diff --git a/hw/ip/spi_host/lint/spi_host.waiver b/hw/ip/spi_host/lint/spi_host.waiver
index 63c8fce..2e68320 100644
--- a/hw/ip/spi_host/lint/spi_host.waiver
+++ b/hw/ip/spi_host/lint/spi_host.waiver
@@ -3,3 +3,14 @@
# SPDX-License-Identifier: Apache-2.0
#
# waiver file for SPI_HOST
+
+# This waiver applies to the SPI_HOST FSM which uses signals next_state_after_idle and
+# next_state_after_idle_csb_active to determine the following state.
+#
+# This is done because in certain conditions the Idle and IdleCSBActive states can be bypassed,
+# meaning the idle state is never actually entered, and the FSM jumps immediately to the appropriate
+# exit state after idle. This allows smooth transitions from one command segment to the other. By
+# using a signal to define the following state, we can be sure that the logic is consistent
+# regardless of whether the idle state is occupied or bypassed.
+
+waive -rules {CALC_NEXT_STATE} -regexp {next_state_after_idle.*}
diff --git a/hw/ip/spi_host/rtl/spi_host.sv b/hw/ip/spi_host/rtl/spi_host.sv
index bfd1e5a..45e22bf 100644
--- a/hw/ip/spi_host/rtl/spi_host.sv
+++ b/hw/ip/spi_host/rtl/spi_host.sv
@@ -251,8 +251,6 @@
// Any qe pin from COMMAND will suffice.
assign command_valid = |cmd_qes;
- `ASSERT(CmdAtomicity_A, ~(&cmd_qes ^ |cmd_qes), clk_i, rst_ni);
-
logic active;
logic rx_stall;
logic tx_stall;
