- * CONFIG_PDC_NARROW has been added to allow 64-bit kernels to run on
- * systems with 32-bit MEM_PDC calls. This will allow wide kernels to
- * run on Cxxx boxes now. -RB
- *
- * Note that some PAT boxes may have 64-bit IODC I/O...
+ * Ryan Bradetich added the now obsolete CONFIG_PDC_NARROW to allow
+ * 64-bit kernels to run on systems with 32-bit MEM_PDC calls.
+ * This allowed wide kernels to run on Cxxx boxes.
+ * We now detect 32-bit-only PDC and dynamically switch to 32-bit mode
+ * when running a 64-bit kernel on such boxes (e.g. C200 or C360).