netdev - [PATCH net-next] mscc: Register poll timeout should be wall time not attempts

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Message-ID: <20181220131631.5520-1-steen.hegelund@microchip.com>
Date:   Thu, 20 Dec 2018 14:16:31 +0100
From:   Steen Hegelund <steen.hegelund@...rochip.com>
To:     <netdev@...r.kernel.org>, <davem@...emloft.net>
CC:     <alexandre.belloni@...tlin.com>,
        Steen Hegelund <steen.hegelund@...rochip.com>
Subject: [PATCH net-next] mscc: Register poll timeout should be wall time not attempts

When doing indirect access in the Ocelot chip, a command is setup,
issued and then we need to poll until the result is ready. The polling
timeout is specified in milliseconds in the datasheet and not in
register access attempts.
It is not a bug on the currently supported platform, but we observed
that the code does not work properly on other platforms that we want to
support as the timing requirements there are different.

Signed-off-by: Steen Hegelund <steen.hegelund@...rochip.com>
---
 drivers/net/ethernet/mscc/ocelot.c | 55 +++++++++++++++---------------
 1 file changed, 27 insertions(+), 28 deletions(-)

diff --git a/drivers/net/ethernet/mscc/ocelot.c b/drivers/net/ethernet/mscc/ocelot.c
index 3238b9ee42f3..debe74e4a041 100644
--- a/drivers/net/ethernet/mscc/ocelot.c
+++ b/drivers/net/ethernet/mscc/ocelot.c
@@ -15,6 +15,7 @@
 #include <linux/netdevice.h>
 #include <linux/phy.h>
 #include <linux/skbuff.h>
+#include <linux/iopoll.h>
 #include <net/arp.h>
 #include <net/netevent.h>
 #include <net/rtnetlink.h>
@@ -22,6 +23,9 @@
 
 #include "ocelot.h"
 
+#define TABLE_UPDATE_SLEEP_US 10
+#define TABLE_UPDATE_TIMEOUT_US 100000
+
 /* MAC table entry types.
  * ENTRYTYPE_NORMAL is subject to aging.
  * ENTRYTYPE_LOCKED is not subject to aging.
@@ -41,23 +45,20 @@ struct ocelot_mact_entry {
 	enum macaccess_entry_type type;
 };
 
-static inline int ocelot_mact_wait_for_completion(struct ocelot *ocelot)
+static inline u32 ocelot_mact_read_macaccess(struct ocelot *ocelot)
 {
-	unsigned int val, timeout = 10;
-
-	/* Wait for the issued mac table command to be completed, or timeout.
-	 * When the command read from  ANA_TABLES_MACACCESS is
-	 * MACACCESS_CMD_IDLE, the issued command completed successfully.
-	 */
-	do {
-		val = ocelot_read(ocelot, ANA_TABLES_MACACCESS);
-		val &= ANA_TABLES_MACACCESS_MAC_TABLE_CMD_M;
-	} while (val != MACACCESS_CMD_IDLE && timeout--);
+	return ocelot_read(ocelot, ANA_TABLES_MACACCESS);
+}
 
-	if (!timeout)
-		return -ETIMEDOUT;
+static inline int ocelot_mact_wait_for_completion(struct ocelot *ocelot)
+{
+	u32 val;
 
-	return 0;
+	return readx_poll_timeout(ocelot_mact_read_macaccess,
+		ocelot, val,
+		(val & ANA_TABLES_MACACCESS_MAC_TABLE_CMD_M) ==
+		MACACCESS_CMD_IDLE,
+		TABLE_UPDATE_SLEEP_US, TABLE_UPDATE_TIMEOUT_US);
 }
 
 static void ocelot_mact_select(struct ocelot *ocelot,
@@ -129,23 +130,21 @@ static void ocelot_mact_init(struct ocelot *ocelot)
 	ocelot_write(ocelot, MACACCESS_CMD_INIT, ANA_TABLES_MACACCESS);
 }
 
-static inline int ocelot_vlant_wait_for_completion(struct ocelot *ocelot)
+static inline u32 ocelot_vlant_read_vlanaccess(struct ocelot *ocelot)
 {
-	unsigned int val, timeout = 10;
-
-	/* Wait for the issued vlan table command to be completed, or timeout.
-	 * When the command read from ANA_TABLES_VLANACCESS is
-	 * VLANACCESS_CMD_IDLE, the issued command completed successfully.
-	 */
-	do {
-		val = ocelot_read(ocelot, ANA_TABLES_VLANACCESS);
-		val &= ANA_TABLES_VLANACCESS_VLAN_TBL_CMD_M;
-	} while (val != ANA_TABLES_VLANACCESS_CMD_IDLE && timeout--);
+	return ocelot_read(ocelot, ANA_TABLES_VLANACCESS);
+}
 
-	if (!timeout)
-		return -ETIMEDOUT;
+static inline int ocelot_vlant_wait_for_completion(struct ocelot *ocelot)
+{
+	u32 val;
 
-	return 0;
+	return readx_poll_timeout(ocelot_vlant_read_vlanaccess,
+		ocelot,
+		val,
+		(val & ANA_TABLES_VLANACCESS_VLAN_TBL_CMD_M) ==
+		ANA_TABLES_VLANACCESS_CMD_IDLE,
+		TABLE_UPDATE_SLEEP_US, TABLE_UPDATE_TIMEOUT_US);
 }
 
 static int ocelot_vlant_set_mask(struct ocelot *ocelot, u16 vid, u32 mask)
-- 
2.20.1