[PATCH AUTOSEL 5.8 31/64] net: phy: mscc: restore the base page in vsc8514/8584_config_init

From: Sasha Levin
Date: Mon Aug 10 2020 - 15:09:53 EST


From: Antoine Tenart <antoine.tenart@xxxxxxxxxxx>

[ Upstream commit 6119dda34e5d0821959e37641b287576826b6378 ]

In the vsc8584_config_init and vsc8514_config_init, the base page is set
to 'GPIO', configuration is done, and the page is never explicitly
restored to the standard page. No bug was triggered as it turns out
helpers called in those config_init functions do modify the base page,
and set it back to standard. But that is dangerous and any modification
to those functions would introduce bugs. This patch fixes this, to
improve maintenance, by restoring the base page to 'standard' once
'GPIO' accesses are completed.

Signed-off-by: Antoine Tenart <antoine.tenart@xxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/net/phy/mscc/mscc_main.c | 9 +++++++++
1 file changed, 9 insertions(+)

diff --git a/drivers/net/phy/mscc/mscc_main.c b/drivers/net/phy/mscc/mscc_main.c
index 5ddc44f87eaf0..8f5f2586e7849 100644
--- a/drivers/net/phy/mscc/mscc_main.c
+++ b/drivers/net/phy/mscc/mscc_main.c
@@ -1379,6 +1379,11 @@ static int vsc8584_config_init(struct phy_device *phydev)
if (ret)
goto err;

+ ret = phy_base_write(phydev, MSCC_EXT_PAGE_ACCESS,
+ MSCC_PHY_PAGE_STANDARD);
+ if (ret)
+ goto err;
+
if (!phy_interface_is_rgmii(phydev)) {
val = PROC_CMD_MCB_ACCESS_MAC_CONF | PROC_CMD_RST_CONF_PORT |
PROC_CMD_READ_MOD_WRITE_PORT;
@@ -1751,7 +1756,11 @@ static int vsc8514_config_init(struct phy_device *phydev)
val &= ~MAC_CFG_MASK;
val |= MAC_CFG_QSGMII;
ret = phy_base_write(phydev, MSCC_PHY_MAC_CFG_FASTLINK, val);
+ if (ret)
+ goto err;

+ ret = phy_base_write(phydev, MSCC_EXT_PAGE_ACCESS,
+ MSCC_PHY_PAGE_STANDARD);
if (ret)
goto err;

--
2.25.1