diff mbox series

[4/7] realtek: clean up rtl838x MDIO busy wait loop

Message ID 20220723205319.3326374-5-jan@3e8.eu
State Accepted
Delegated to: Daniel Golle
Headers show
Series realtek: add HPE 1920 support | expand

Commit Message

Jan Hoffmann July 23, 2022, 8:53 p.m. UTC 
Don't use udelay to allow other kernel tasks to execute if the kernel
has been built without preemption. Also determine the timeout based on
jiffies instead of loop iterations.

This is especially important on devices containing a watchdog with a
short timeout. Without this change, the watchdog is not serviced during
PHY patching which can take multiple seconds.

Signed-off-by: Jan Hoffmann <jan@3e8.eu>
---
 .../drivers/net/dsa/rtl83xx/rtl838x.c         | 37 +++++++++++--------
 1 file changed, 22 insertions(+), 15 deletions(-)

Comments

Birger Koblitz July 24, 2022, 6:03 a.m. UTC | #1 
On 7/23/22 22:53, Jan Hoffmann wrote:
> Don't use udelay to allow other kernel tasks to execute if the kernel
> has been built without preemption. Also determine the timeout based on
> jiffies instead of loop iterations.

Tested on a D-Link DGS-1210-16.
diff mbox series

Patch

diff --git a/target/linux/realtek/files-5.10/drivers/net/dsa/rtl83xx/rtl838x.c b/target/linux/realtek/files-5.10/drivers/net/dsa/rtl83xx/rtl838x.c
index cdf176677805..524594d725fc 100644
--- a/target/linux/realtek/files-5.10/drivers/net/dsa/rtl83xx/rtl838x.c
+++ b/target/linux/realtek/files-5.10/drivers/net/dsa/rtl83xx/rtl838x.c
@@ -1805,13 +1805,20 @@  irqreturn_t rtl838x_switch_irq(int irq, void *dev_id)
 
 int rtl838x_smi_wait_op(int timeout)
 {
-	do {
-		timeout--;
-		udelay(10);
-	} while ((sw_r32(RTL838X_SMI_ACCESS_PHY_CTRL_1) & 0x1) && (timeout >= 0));
-	if (timeout <= 0)
-		return -1;
-	return 0;
+	unsigned long end = jiffies + usecs_to_jiffies(timeout);
+
+	while (1) {
+		if (!(sw_r32(RTL838X_SMI_ACCESS_PHY_CTRL_1) & 0x1))
+			return 0;
+
+		if (time_after(jiffies, end))
+			break;
+
+		usleep_range(10, 20);
+	}
+
+	pr_err("rtl838x_smi_wait_op: timeout\n");
+	return -1;
 }
 
 /*
@@ -1832,7 +1839,7 @@  int rtl838x_read_phy(u32 port, u32 page, u32 reg, u32 *val)
 
 	mutex_lock(&smi_lock);
 
-	if (rtl838x_smi_wait_op(10000))
+	if (rtl838x_smi_wait_op(100000))
 		goto timeout;
 
 	sw_w32_mask(0xffff0000, port << 16, RTL838X_SMI_ACCESS_PHY_CTRL_2);
@@ -1842,7 +1849,7 @@  int rtl838x_read_phy(u32 port, u32 page, u32 reg, u32 *val)
 	sw_w32(v | park_page, RTL838X_SMI_ACCESS_PHY_CTRL_1);
 	sw_w32_mask(0, 1, RTL838X_SMI_ACCESS_PHY_CTRL_1);
 
-	if (rtl838x_smi_wait_op(10000))
+	if (rtl838x_smi_wait_op(100000))
 		goto timeout;
 
 	*val = sw_r32(RTL838X_SMI_ACCESS_PHY_CTRL_2) & 0xffff;
@@ -1868,7 +1875,7 @@  int rtl838x_write_phy(u32 port, u32 page, u32 reg, u32 val)
 		return -ENOTSUPP;
 
 	mutex_lock(&smi_lock);
-	if (rtl838x_smi_wait_op(10000))
+	if (rtl838x_smi_wait_op(100000))
 		goto timeout;
 
 	sw_w32(BIT(port), RTL838X_SMI_ACCESS_PHY_CTRL_0);
@@ -1881,7 +1888,7 @@  int rtl838x_write_phy(u32 port, u32 page, u32 reg, u32 val)
 	sw_w32(v | park_page, RTL838X_SMI_ACCESS_PHY_CTRL_1);
 	sw_w32_mask(0, 1, RTL838X_SMI_ACCESS_PHY_CTRL_1);
 
-	if (rtl838x_smi_wait_op(10000))
+	if (rtl838x_smi_wait_op(100000))
 		goto timeout;
 
 	mutex_unlock(&smi_lock);
@@ -1901,7 +1908,7 @@  int rtl838x_read_mmd_phy(u32 port, u32 addr, u32 reg, u32 *val)
 
 	mutex_lock(&smi_lock);
 
-	if (rtl838x_smi_wait_op(10000))
+	if (rtl838x_smi_wait_op(100000))
 		goto timeout;
 
 	sw_w32(1 << port, RTL838X_SMI_ACCESS_PHY_CTRL_0);
@@ -1916,7 +1923,7 @@  int rtl838x_read_mmd_phy(u32 port, u32 addr, u32 reg, u32 *val)
 	v = 1 << 1 | 0 << 2 | 1;
 	sw_w32(v, RTL838X_SMI_ACCESS_PHY_CTRL_1);
 
-	if (rtl838x_smi_wait_op(10000))
+	if (rtl838x_smi_wait_op(100000))
 		goto timeout;
 
 	*val = sw_r32(RTL838X_SMI_ACCESS_PHY_CTRL_2) & 0xffff;
@@ -1940,7 +1947,7 @@  int rtl838x_write_mmd_phy(u32 port, u32 addr, u32 reg, u32 val)
 	val &= 0xffff;
 	mutex_lock(&smi_lock);
 
-	if (rtl838x_smi_wait_op(10000))
+	if (rtl838x_smi_wait_op(100000))
 		goto timeout;
 
 	sw_w32(1 << port, RTL838X_SMI_ACCESS_PHY_CTRL_0);
@@ -1954,7 +1961,7 @@  int rtl838x_write_mmd_phy(u32 port, u32 addr, u32 reg, u32 val)
 	v = 1 << 1 | 1 << 2 | 1;
 	sw_w32(v, RTL838X_SMI_ACCESS_PHY_CTRL_1);
 
-	if (rtl838x_smi_wait_op(10000))
+	if (rtl838x_smi_wait_op(100000))
 		goto timeout;
 
 	mutex_unlock(&smi_lock);