Commits on Apr 30, 2024

1. [chip,dv] Wait for JTAG connection in chip_sw_base_vseq …

   The wait_lc_status() task does a DMI read over JTAG to figure out the
   current state of lc_ctrl. This requires pinmux to route the JTAG
   signals to LC_CTRL and things get rather confused if we run this task
   before the routing has happened.
   
   In normal use, the JTAG driver will send an IR command to switch
   address to the DMI address. Then it will send a DR command to do the
   DMI read/write. On the next DMI command, it can avoid the silly extra
   IR command because it knows we're already pointing at the DMI address.
   
   Of course, this doesn't work if the JTAG signals got squashed. In that
   case, it will not know that IR hasn't changed, so it will send
   repeated DR commands expecting to see a particular lc_ctrl status come
   out. But that won't happen because we're not actually looking at the
   DMI register at all. Oops!
   
   This commit adds a wait to make sure that JTAG has actually been
   connected up.
   
   Signed-off-by: Rupert Swarbrick <rswarbrick@lowrisc.org>

   

   rswarbrick committed Apr 30, 2024
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