+static void ag71xx_dma_reset(struct ag71xx *ag)
+{
+ u32 val;
+ int i;
+
+ ag71xx_dump_dma_regs(ag);
+
+ /* stop RX and TX */
+ ag71xx_wr(ag, AG71XX_REG_RX_CTRL, 0);
+ ag71xx_wr(ag, AG71XX_REG_TX_CTRL, 0);
+
+ /*
+ * give the hardware some time to really stop all rx/tx activity
+ * clearing the descriptors too early causes random memory corruption
+ */
+ mdelay(1);
+
+ /* clear descriptor addresses */
+ ag71xx_wr(ag, AG71XX_REG_TX_DESC, 0);
+ ag71xx_wr(ag, AG71XX_REG_RX_DESC, 0);
+
+ /* clear pending RX/TX interrupts */
+ for (i = 0; i < 256; i++) {
+ ag71xx_wr(ag, AG71XX_REG_RX_STATUS, RX_STATUS_PR);
+ ag71xx_wr(ag, AG71XX_REG_TX_STATUS, TX_STATUS_PS);
+ }
+
+ /* clear pending errors */
+ ag71xx_wr(ag, AG71XX_REG_RX_STATUS, RX_STATUS_BE | RX_STATUS_OF);
+ ag71xx_wr(ag, AG71XX_REG_TX_STATUS, TX_STATUS_BE | TX_STATUS_UR);
+
+ val = ag71xx_rr(ag, AG71XX_REG_RX_STATUS);
+ if (val)
+ printk(KERN_ALERT "%s: unable to clear DMA Rx status: %08x\n",
+ ag->dev->name, val);
+
+ val = ag71xx_rr(ag, AG71XX_REG_TX_STATUS);
+
+ /* mask out reserved bits */
+ val &= ~0xff000000;
+
+ if (val)
+ printk(KERN_ALERT "%s: unable to clear DMA Tx status: %08x\n",
+ ag->dev->name, val);
+
+ ag71xx_dump_dma_regs(ag);
+}
+
+static void ag71xx_hw_start(struct ag71xx *ag)
+{
+ /* start RX engine */
+ ag71xx_wr(ag, AG71XX_REG_RX_CTRL, RX_CTRL_RXE);
+
+ /* enable interrupts */
+ ag71xx_wr(ag, AG71XX_REG_INT_ENABLE, AG71XX_INT_INIT);
+}
+
+static void ag71xx_hw_stop(struct ag71xx *ag)
+{
+ /* disable all interrupts */
+ ag71xx_wr(ag, AG71XX_REG_INT_ENABLE, 0);
+
+ ag71xx_dma_reset(ag);
+}
+