e1000: Fix RSS if enabled in mid-connection
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: John Ronciak <john.ronciak@intel.com>
diff --git a/drivers/net/e1000/e1000_hw.c b/drivers/net/e1000/e1000_hw.c
index 1b8869e..5ee42c7 100644
--- a/drivers/net/e1000/e1000_hw.c
+++ b/drivers/net/e1000/e1000_hw.c
@@ -4755,8 +4755,36 @@
rar_low = ((uint32_t) addr[0] |
((uint32_t) addr[1] << 8) |
((uint32_t) addr[2] << 16) | ((uint32_t) addr[3] << 24));
+ rar_high = ((uint32_t) addr[4] | ((uint32_t) addr[5] << 8));
- rar_high = ((uint32_t) addr[4] | ((uint32_t) addr[5] << 8) | E1000_RAH_AV);
+ /* Disable Rx and flush all Rx frames before enabling RSS to avoid Rx
+ * unit hang.
+ *
+ * Description:
+ * If there are any Rx frames queued up or otherwise present in the HW
+ * before RSS is enabled, and then we enable RSS, the HW Rx unit will
+ * hang. To work around this issue, we have to disable receives and
+ * flush out all Rx frames before we enable RSS. To do so, we modify we
+ * redirect all Rx traffic to manageability and then reset the HW.
+ * This flushes away Rx frames, and (since the redirections to
+ * manageability persists across resets) keeps new ones from coming in
+ * while we work. Then, we clear the Address Valid AV bit for all MAC
+ * addresses and undo the re-direction to manageability.
+ * Now, frames are coming in again, but the MAC won't accept them, so
+ * far so good. We now proceed to initialize RSS (if necessary) and
+ * configure the Rx unit. Last, we re-enable the AV bits and continue
+ * on our merry way.
+ */
+ switch (hw->mac_type) {
+ case e1000_82571:
+ case e1000_82572:
+ if (hw->leave_av_bit_off == TRUE)
+ break;
+ default:
+ /* Indicate to hardware the Address is Valid. */
+ rar_high |= E1000_RAH_AV;
+ break;
+ }
E1000_WRITE_REG_ARRAY(hw, RA, (index << 1), rar_low);
E1000_WRITE_REG_ARRAY(hw, RA, ((index << 1) + 1), rar_high);