[PATCH v4 6/7] net: pch_gbe: Allow longer for resets

[Paul Burton <paul.burton@imgtec.com>]

Resets of the EG20T MAC on the MIPS Boston development board take longer
than the 1000 loops that pch_gbe_wait_clr_bit was performing. Rather
than simply increasing the number of loops, switch to using
readl_poll_timeout_atomic() from linux/iopoll.h in order to provide some
independence from the speed of the CPU.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jarod Wilson <jarod@redhat.com>
Cc: Tobias Klauser <tklauser@distanz.ch>
Cc: linux-mips@linux-mips.org
Cc: netdev@vger.kernel.org

---

Changes in v4: None

Changes in v3:
- Switch to using readl_poll_timeout_atomic().

Changes in v2: None

 drivers/net/ethernet/oki-semi/pch_gbe/pch_gbe_main.c | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/drivers/net/ethernet/oki-semi/pch_gbe/pch_gbe_main.c b/drivers/net/ethernet/oki-semi/pch_gbe/pch_gbe_main.c
index c8554d3adf1c..c109646803a4 100644
--- a/drivers/net/ethernet/oki-semi/pch_gbe/pch_gbe_main.c
+++ b/drivers/net/ethernet/oki-semi/pch_gbe/pch_gbe_main.c
@@ -24,6 +24,7 @@
 #include <linux/ptp_classify.h>
 #include <linux/gpio.h>
 #include <linux/gpio/consumer.h>
+#include <linux/iopoll.h>
 #include <linux/of_gpio.h>
 
 #define DRV_VERSION     "1.01"
@@ -318,13 +319,11 @@ s32 pch_gbe_mac_read_mac_addr(struct pch_gbe_hw *hw)
  */
 static void pch_gbe_wait_clr_bit(void *reg, u32 bit)
 {
+	int err;
 	u32 tmp;
 
-	/* wait busy */
-	tmp = 1000;
-	while ((ioread32(reg) & bit) && --tmp)
-		cpu_relax();
-	if (!tmp)
+	err = readl_poll_timeout_atomic(reg, tmp, !(tmp & bit), 10, 500);
+	if (err)
 		pr_err("Error: busy bit is not cleared\n");
 }
 
-- 
2.13.0