This is a note to let you know that I've just added the patch titled net: axienet: Wait for PhyRstCmplt after core reset to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: net-axienet-wait-for-phyrstcmplt-after-core-reset.patch and it can be found in the queue-4.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From b400c2f4f4c53c86594dd57098970d97d488bfde Mon Sep 17 00:00:00 2001 From: Robert Hancock <robert.hancock@xxxxxxxxxx> Date: Tue, 18 Jan 2022 15:41:25 -0600 Subject: net: axienet: Wait for PhyRstCmplt after core reset From: Robert Hancock <robert.hancock@xxxxxxxxxx> commit b400c2f4f4c53c86594dd57098970d97d488bfde upstream. When resetting the device, wait for the PhyRstCmplt bit to be set in the interrupt status register before continuing initialization, to ensure that the core is actually ready. When using an external PHY, this also ensures we do not start trying to access the PHY while it is still in reset. The PHY reset is initiated by the core reset which is triggered just above, but remains asserted for 5ms after the core is reset according to the documentation. The MgtRdy bit could also be waited for, but unfortunately when using 7-series devices, the bit does not appear to work as documented (it seems to behave as some sort of link state indication and not just an indication the transceiver is ready) so it can't really be relied on for this purpose. Fixes: 8a3b7a252dca9 ("drivers/net/ethernet/xilinx: added Xilinx AXI Ethernet driver") Signed-off-by: Robert Hancock <robert.hancock@xxxxxxxxxx> Reviewed-by: Andrew Lunn <andrew@xxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/net/ethernet/xilinx/xilinx_axienet_main.c | 10 ++++++++++ 1 file changed, 10 insertions(+) --- a/drivers/net/ethernet/xilinx/xilinx_axienet_main.c +++ b/drivers/net/ethernet/xilinx/xilinx_axienet_main.c @@ -278,6 +278,16 @@ static int axienet_dma_bd_init(struct ne axienet_dma_out32(lp, XAXIDMA_TX_CR_OFFSET, cr | XAXIDMA_CR_RUNSTOP_MASK); + /* Wait for PhyRstCmplt bit to be set, indicating the PHY reset has finished */ + ret = read_poll_timeout(axienet_ior, value, + value & XAE_INT_PHYRSTCMPLT_MASK, + DELAY_OF_ONE_MILLISEC, 50000, false, lp, + XAE_IS_OFFSET); + if (ret) { + dev_err(lp->dev, "%s: timeout waiting for PhyRstCmplt\n", __func__); + return ret; + } + return 0; out: axienet_dma_bd_release(ndev); Patches currently in stable-queue which might be from robert.hancock@xxxxxxxxxx are queue-4.9/net-axienet-wait-for-phyrstcmplt-after-core-reset.patch