[PATCH 5.12 076/242] net: phy: realtek: add delay to fix RXC generation issue

Greg Kroah-Hartman
2021-07-15T19:07:59Z

From: Joakim Zhang <qiangqing.zhang@nxp.com>

[ Upstream commit 6813cc8cfdaf401476e1a007cec8ae338cefa573 ]

PHY will delay about 11.5ms to generate RXC clock when switching from
power down to normal operation. Read/write registers would also cause RXC
become unstable and stop for a while during this process. Realtek engineer
suggests 15ms or more delay can workaround this issue.

Signed-off-by: Joakim Zhang <qiangqing.zhang@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/phy/realtek.c | 15 ++++++++++++++-
1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/drivers/net/phy/realtek.c b/drivers/net/phy/realtek.c
index 821e85a97367..7b99a3234c65 100644
--- a/drivers/net/phy/realtek.c
+++ b/drivers/net/phy/realtek.c
@@ -357,6 +357,19 @@ static int rtl8211f_config_init(struct phy_device *phydev)
return 0;
}

+static int rtl821x_resume(struct phy_device *phydev)
+{
+ int ret;
+
+ ret = genphy_resume(phydev);
+ if (ret < 0)
+ return ret;
+
+ msleep(20);
+
+ return 0;
+}
+
static int rtl8211e_config_init(struct phy_device *phydev)
{
int ret = 0, oldpage;
@@ -852,7 +865,7 @@ static struct phy_driver realtek_drvs[] = {
.config_intr = &rtl8211f_config_intr,
.handle_interrupt = rtl8211f_handle_interrupt,
.suspend = genphy_suspend,
- .resume = genphy_resume,
+ .resume = rtl821x_resume,
.read_page = rtl821x_read_page,
.write_page = rtl821x_write_page,
}, {
--
2.30.2