diff mbox series

[net-next,2/7] net: phy: Allow flagging PHY devices that can't isolate their MII

Message ID 20240911212713.2178943-3-maxime.chevallier@bootlin.com (mailing list archive)
State Changes Requested
Delegated to: Netdev Maintainers
Headers show
Series Allow controlling PHY loopback and isolate modes | expand

Checks

Context Check Description
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for net-next
netdev/ynl success Generated files up to date; no warnings/errors; GEN HAS DIFF 2 files changed, 121 insertions(+);
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 16 this patch: 16
netdev/build_tools success Errors and warnings before: 0 this patch: 0
netdev/cc_maintainers success CCed 7 of 7 maintainers
netdev/build_clang success Errors and warnings before: 29 this patch: 29
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 401 this patch: 401
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 30 lines checked
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 70 this patch: 70
netdev/source_inline success Was 0 now: 0

Commit Message

Maxime Chevallier Sept. 11, 2024, 9:27 p.m. UTC 
Some PHYs have malfunctionning isolation modes, where the MII lines
aren't correctly set in high-impedance, potentially interfering with the
MII bus in unexpected ways. Some other PHYs simply don't support it.

Allow flagging these PHYs, and prevent isolating them altogether.

Assume the PHY can isolate by default.

Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
---
 drivers/net/phy/phy_device.c | 11 +++++++++++
 include/linux/phy.h          |  1 +
 2 files changed, 12 insertions(+)
diff mbox series

Patch

diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
index c468e72bef4b..2a3db1043626 100644
--- a/drivers/net/phy/phy_device.c
+++ b/drivers/net/phy/phy_device.c
@@ -2127,6 +2127,14 @@  int phy_loopback(struct phy_device *phydev, bool enable)
 }
 EXPORT_SYMBOL(phy_loopback);
 
+static bool phy_can_isolate(struct phy_device *phydev)
+{
+	if (phydev->drv)
+		return !(phydev->drv->flags & PHY_NO_ISOLATE);
+
+	return true;
+}
+
 int phy_isolate(struct phy_device *phydev, bool enable)
 {
 	int ret = 0;
@@ -2134,6 +2142,9 @@  int phy_isolate(struct phy_device *phydev, bool enable)
 	if (!phydev->drv)
 		return -EIO;
 
+	if (!phy_can_isolate(phydev))
+		return -EOPNOTSUPP;
+
 	mutex_lock(&phydev->lock);
 
 	if (enable && phydev->isolated) {
diff --git a/include/linux/phy.h b/include/linux/phy.h
index ae33919aa0f5..f0a8a5459fbe 100644
--- a/include/linux/phy.h
+++ b/include/linux/phy.h
@@ -90,6 +90,7 @@  extern const int phy_10gbit_features_array[1];
 #define PHY_RST_AFTER_CLK_EN	0x00000002
 #define PHY_POLL_CABLE_TEST	0x00000004
 #define PHY_ALWAYS_CALL_SUSPEND	0x00000008
+#define PHY_NO_ISOLATE		0x00000010
 #define MDIO_DEVICE_IS_PHY	0x80000000
 
 /**