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Date: Mon, 24 Oct 2016 11:25:40 +0200
From: Manfred Schlaegl <manfred.schlaegl@...zinger.com>
To: Fugang Duan <fugang.duan@....com>
Cc: netdev@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [PATCH] net: fec: hard phy reset on open
We have seen some problems with auto negotiation on i.MX6 using LAN8720,
after interface down/up.
In our configuration, the ptp clock is used externally as reference
clock for the phy. Some phys (e.g. LAN8720) needs a stable clock while
and after hard reset.
Before this patch, the driver disabled the clock on close but did no
hard reset on open, after enabling the clocks again.
A solution that prevents disabling the clocks on close was considered,
but discarded because of bad power saving behavior.
This patch saves the reset dt properties on probe and does a reset on
every open after clocks where enabled, to make sure the clock is stable
while and after hard reset.
Tested on i.MX6 and i.MX28, both using LAN8720.
Signed-off-by: Manfred Schlaegl <manfred.schlaegl@...zinger.com>
---
drivers/net/ethernet/freescale/fec.h | 4 ++
drivers/net/ethernet/freescale/fec_main.c | 77 +++++++++++++++++--------------
2 files changed, 47 insertions(+), 34 deletions(-)
diff --git a/drivers/net/ethernet/freescale/fec.h b/drivers/net/ethernet/freescale/fec.h
index c865135..379e619 100644
--- a/drivers/net/ethernet/freescale/fec.h
+++ b/drivers/net/ethernet/freescale/fec.h
@@ -498,6 +498,10 @@ struct fec_enet_private {
struct clk *clk_enet_out;
struct clk *clk_ptp;
+ int phy_reset;
+ bool phy_reset_active_high;
+ int phy_reset_msec;
+
bool ptp_clk_on;
struct mutex ptp_clk_mutex;
unsigned int num_tx_queues;
diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c
index 48a033e..8cc1ec5 100644
--- a/drivers/net/ethernet/freescale/fec_main.c
+++ b/drivers/net/ethernet/freescale/fec_main.c
@@ -2802,6 +2802,22 @@ static int fec_enet_alloc_buffers(struct net_device *ndev)
return 0;
}
+static void fec_reset_phy(struct fec_enet_private *fep)
+{
+ if (!gpio_is_valid(fep->phy_reset))
+ return;
+
+ gpio_set_value_cansleep(fep->phy_reset, !!fep->phy_reset_active_high);
+
+ if (fep->phy_reset_msec > 20)
+ msleep(fep->phy_reset_msec);
+ else
+ usleep_range(fep->phy_reset_msec * 1000,
+ fep->phy_reset_msec * 1000 + 1000);
+
+ gpio_set_value_cansleep(fep->phy_reset, !fep->phy_reset_active_high);
+}
+
static int
fec_enet_open(struct net_device *ndev)
{
@@ -2817,6 +2833,8 @@ fec_enet_open(struct net_device *ndev)
if (ret)
goto clk_enable;
+ fec_reset_phy(fep);
+
/* I should reset the ring buffers here, but I don't yet know
* a simple way to do that.
*/
@@ -3183,52 +3201,39 @@ static int fec_enet_init(struct net_device *ndev)
return 0;
}
-#ifdef CONFIG_OF
-static void fec_reset_phy(struct platform_device *pdev)
+static int
+fec_get_reset_phy(struct platform_device *pdev, int *msec, int *phy_reset,
+ bool *active_high)
{
- int err, phy_reset;
- bool active_high = false;
- int msec = 1;
+ int err;
struct device_node *np = pdev->dev.of_node;
- if (!np)
- return;
+ if (!np || !of_device_is_available(np))
+ return 0;
- of_property_read_u32(np, "phy-reset-duration", &msec);
+ of_property_read_u32(np, "phy-reset-duration", msec);
/* A sane reset duration should not be longer than 1s */
- if (msec > 1000)
- msec = 1;
+ if (*msec > 1000)
+ *msec = 1;
- phy_reset = of_get_named_gpio(np, "phy-reset-gpios", 0);
- if (!gpio_is_valid(phy_reset))
- return;
+ *phy_reset = of_get_named_gpio(np, "phy-reset-gpios", 0);
+ if (!gpio_is_valid(*phy_reset))
+ return 0;
- active_high = of_property_read_bool(np, "phy-reset-active-high");
+ *active_high = of_property_read_bool(np, "phy-reset-active-high");
- err = devm_gpio_request_one(&pdev->dev, phy_reset,
- active_high ? GPIOF_OUT_INIT_HIGH : GPIOF_OUT_INIT_LOW,
- "phy-reset");
+ err = devm_gpio_request_one(&pdev->dev, *phy_reset,
+ *active_high ?
+ GPIOF_OUT_INIT_HIGH :
+ GPIOF_OUT_INIT_LOW,
+ "phy-reset");
if (err) {
dev_err(&pdev->dev, "failed to get phy-reset-gpios: %d\n", err);
- return;
+ return err;
}
- if (msec > 20)
- msleep(msec);
- else
- usleep_range(msec * 1000, msec * 1000 + 1000);
-
- gpio_set_value_cansleep(phy_reset, !active_high);
-}
-#else /* CONFIG_OF */
-static void fec_reset_phy(struct platform_device *pdev)
-{
- /*
- * In case of platform probe, the reset has been done
- * by machine code.
- */
+ return 0;
}
-#endif /* CONFIG_OF */
static void
fec_enet_get_queue_num(struct platform_device *pdev, int *num_tx, int *num_rx)
@@ -3409,7 +3414,10 @@ fec_probe(struct platform_device *pdev)
pm_runtime_set_active(&pdev->dev);
pm_runtime_enable(&pdev->dev);
- fec_reset_phy(pdev);
+ ret = fec_get_reset_phy(pdev, &fep->phy_reset_msec, &fep->phy_reset,
+ &fep->phy_reset_active_high);
+ if (ret)
+ goto failed_reset;
if (fep->bufdesc_ex)
fec_ptp_init(pdev);
@@ -3467,6 +3475,7 @@ fec_probe(struct platform_device *pdev)
failed_mii_init:
failed_irq:
failed_init:
+failed_reset:
fec_ptp_stop(pdev);
if (fep->reg_phy)
regulator_disable(fep->reg_phy);
--
2.1.4
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