+
+static void radeon_fixup_offset(struct radeonfb_info *rinfo)
+{
+ u32 local_base;
+
+ /* *** Ugly workaround *** */
+ /*
+ * On some platforms, the video memory is mapped at 0 in radeon chip space
+ * (like PPCs) by the firmware. X will always move it up so that it's seen
+ * by the chip to be at the same address as the PCI BAR.
+ * That means that when switching back from X, there is a mismatch between
+ * the offsets programmed into the engine. This means that potentially,
+ * accel operations done before radeonfb has a chance to re-init the engine
+ * will have incorrect offsets, and potentially trash system memory !
+ *
+ * The correct fix is for fbcon to never call any accel op before the engine
+ * has properly been re-initialized (by a call to set_var), but this is a
+ * complex fix. This workaround in the meantime, called before every accel
+ * operation, makes sure the offsets are in sync.
+ */
+
+ radeon_fifo_wait (1);
+ local_base = INREG(MC_FB_LOCATION) << 16;
+ if (local_base == rinfo->fb_local_base)
+ return;
+
+ rinfo->fb_local_base = local_base;
+
+ radeon_fifo_wait (3);
+ OUTREG(DEFAULT_PITCH_OFFSET, (rinfo->pitch << 0x16) |
+ (rinfo->fb_local_base >> 10));
+ OUTREG(DST_PITCH_OFFSET, (rinfo->pitch << 0x16) | (rinfo->fb_local_base >> 10));
+ OUTREG(SRC_PITCH_OFFSET, (rinfo->pitch << 0x16) | (rinfo->fb_local_base >> 10));
+}
+