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When generating the default LRC, if a register is not masked, we apply any save-restore programming necessary via a read-modify-write sequence that will ensure we only update the relevant bits/fields without clobbering the rest of the register. However some of the registers that need to be updated might be MCR registers which require steering to a non-terminated instance to ensure we can read back a valid, non-zero value. The steering of reads originating from a command streamer is controlled by register CS_MMIO_GROUP_INSTANCE_SELECT. Emit additional MI_LRI commands to update the steering before any RMW of an MCR register to ensure the reads are performed properly. Note that needing to perform a RMW of an MCR register while building the default LRC is pretty rare. Most of the MCR registers that are part of an engine's LRCs are also masked registers, so no MCR is necessary. Fixes:f2f90989cc("drm/xe: Avoid reading RMW registers in emit_wa_job") Cc: Michal Wajdeczko <michal.wajdeczko@intel.com> Reviewed-by: Balasubramani Vivekanandan <balasubramani.vivekanandan@intel.com> Link: https://patch.msgid.link/20260206223058.387014-2-matthew.d.roper@intel.com Signed-off-by: Matt Roper <matthew.d.roper@intel.com> (cherry picked from commit6c2e331c91) Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>