we always set ->SCp.ptr to physical address of buffer; for DMA that's
just what we need, but we end up using it as virtual address in PIO
case of esp_do_data(), with obvious breakage as soon as memory mapping
becomes non-trivial.  The fix is obvious.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
                 */
                int oldphase, i = 0; /* or where we left off last time ?? esp->current_data ?? */
                int fifocnt = 0;
+               unsigned char *p = phys_to_virt((unsigned long)SCptr->SCp.ptr);
 
                oldphase = esp_read(eregs->esp_status) & ESP_STAT_PMASK;
 
 
                                /* read fifo */
                                for(j=0;j<fifocnt;j++)
-                                       SCptr->SCp.ptr[i++] = esp_read(eregs->esp_fdata);
+                                       p[i++] = esp_read(eregs->esp_fdata);
 
                                ESPDATA(("(%d) ", i));
 
 
                                /* fill fifo */
                                for(j=0;j<this_count;j++)
-                                       esp_write(eregs->esp_fdata, SCptr->SCp.ptr[i++]);
+                                       esp_write(eregs->esp_fdata, p[i++]);
 
                                /* how many left if this goes out ?? */
                                hmuch -= this_count;