<snip>

On Tue, Oct 30, 2018 at 10:31:39AM +0100, Kurt Kanzenbach wrote:

quoted

The function could report a false positive if it gets preempted between

reading

quoted

the XEL_MDIOCTRL_OFFSET register and checking for the timeout.  In such a

case,

quoted

the condition has to be rechecked to avoid false positives.

Therefore, check for expected condition even after the timeout occurred.

Signed-off-by: Kurt Kanzenbach <kurt@linutronix.de>
---
 drivers/net/ethernet/xilinx/xilinx_emaclite.c | 20 +++++++++++++++-----
 1 file changed, 15 insertions(+), 5 deletions(-)

diff --git a/drivers/net/ethernet/xilinx/xilinx_emaclite.c

b/drivers/net/ethernet/xilinx/xilinx_emaclite.c

quoted

index 639e3e99af46..957d03085bd0 100644

--- a/drivers/net/ethernet/xilinx/xilinx_emaclite.c
+++ b/drivers/net/ethernet/xilinx/xilinx_emaclite.c

@@ -714,19 +714,29 @@ static irqreturn_t xemaclite_interrupt(int irq, void

*dev_id)

quoted

 static int xemaclite_mdio_wait(struct net_local *lp)
 {
 	unsigned long end = jiffies + 2;
+	u32 val;

 	/* wait for the MDIO interface to not be busy or timeout
 	 * after some time.
 	 */
-	while (xemaclite_readl(lp->base_addr + XEL_MDIOCTRL_OFFSET) &
-			XEL_MDIOCTRL_MDIOSTS_MASK) {
+	while (1) {
+		val = xemaclite_readl(lp->base_addr +

XEL_MDIOCTRL_OFFSET);

Hi Kurt

It looks like readx_poll_timeout() should work here.

Yes, valid point. readx_poll_timeout API repoll addr after timeout.
Reusing it would simplify the flow.

   Andrew