[PATCH]: 1ba58a4d24 target/riscv/riscv-013.c: dmi_scan() line 522. Making use of dtmcs_idle.

[gerrit]

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"Paul Robertson <ethelthef...@gmail.com>" just uploaded a new patch set to 
Gerrit, which you can find at https://review.openocd.org/c/openocd/+/7085

-- gerrit

commit 1ba58a4d24e844adfcd5378bfa9f5a8b3cfd1024
Author: Ethelthefrog <ethelthef...@gmail.com>
Date:   Thu Jul 14 14:26:26 2022 +0100

    target/riscv/riscv-013.c: dmi_scan() line 522.  Making use of dtmcs_idle.
    
    RISC-V debug spec section 6.1.4 specifies the 'idle' field in the dtmcs 
register
    as a hint for avoid hitting 'busy' returns during DMI transactions.  This 
patch
    uses this value (stored in info->dtmcs_idle) as a minimum value for 
idle_count.
    
    Signed-off-by: Ethelthefrog <ethelthef...@gmail.com>
    Change-Id: Ie7460cc6d5ce872d97e508c7de17a1666bc623c5

diff --git a/.gitignore b/.gitignore
index f5aa68a405..c582504cd4 100644
--- a/.gitignore
+++ b/.gitignore
@@ -101,3 +101,12 @@ tags
 GPATH
 GRTAGS
 GTAGS
+
+# Qt Creator stuff
+openocd.cflags
+openocd.config
+openocd.creator*
+openocd.cxxflags
+openocd.files
+openocd.includes
+
diff --git a/src/target/riscv/riscv-013.c b/src/target/riscv/riscv-013.c
index 1b1450a7dc..ae37d3bfc2 100644
--- a/src/target/riscv/riscv-013.c
+++ b/src/target/riscv/riscv-013.c
@@ -519,6 +519,13 @@ static dmi_status_t dmi_scan(struct target *target, 
uint32_t *address_in,
        if (exec)
                idle_count += info->ac_busy_delay;
 
+       /* The target can request a minimum number of TCK cycles in RunTest/Idle
+          to enable clock-domain-crossing logic to get values from the JTAG
+          domain to the core clock domain and back again. */
+       int min_idle_count = ((int)info->dtmcs_idle)-1;
+       if (idle_count < min_idle_count)
+               idle_count = min_idle_count;
+
        if (idle_count)
                jtag_add_runtest(idle_count, TAP_IDLE);
 

--