fm10k: don't clear the RXQCTL register when enabling or disabling queues

Ensure that other bits in the RXQCTL register do not get cleared. This
ensures that bits related to queue ownership are maintained.
Signed-off-by: NJacob Keller <jacob.e.keller@intel.com>
Tested-by: NKrishneil Singh <Krishneil.k.singh@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ethernet/intel/fm10k/fm10k_pci.c

@@ -734,15 +734,15 @@ static void fm10k_configure_rx_ring(struct fm10k_intfc *interface,
 	u64 rdba = ring->dma;
 	struct fm10k_hw *hw = &interface->hw;
 	u32 size = ring->count * sizeof(union fm10k_rx_desc);
-	u32 rxqctl = FM10K_RXQCTL_ENABLE | FM10K_RXQCTL_PF;
-	u32 rxdctl = FM10K_RXDCTL_WRITE_BACK_MIN_DELAY;
+	u32 rxqctl, rxdctl = FM10K_RXDCTL_WRITE_BACK_MIN_DELAY;
 	u32 srrctl = FM10K_SRRCTL_BUFFER_CHAINING_EN;
 	u32 rxint = FM10K_INT_MAP_DISABLE;
 	u8 rx_pause = interface->rx_pause;
 	u8 reg_idx = ring->reg_idx;
 
 	/* disable queue to avoid issues while updating state */
-	fm10k_write_reg(hw, FM10K_RXQCTL(reg_idx), 0);
+	rxqctl = fm10k_read_reg(hw, FM10K_RXQCTL(reg_idx));
+	rxqctl &= ~FM10K_RXQCTL_ENABLE;
 	fm10k_write_flush(hw);
 
 	/* possible poll here to verify ring resources have been cleaned */
@@ -797,6 +797,8 @@ static void fm10k_configure_rx_ring(struct fm10k_intfc *interface,
 	fm10k_write_reg(hw, FM10K_RXINT(reg_idx), rxint);
 
 	/* enable queue */
+	rxqctl = fm10k_read_reg(hw, FM10K_RXQCTL(reg_idx));
+	rxqctl |= FM10K_RXQCTL_ENABLE;
 	fm10k_write_reg(hw, FM10K_RXQCTL(reg_idx), rxqctl);
 
 	/* place buffers on ring for receive data */