diff mbox series

[v1,net] net: phy: Micrel KSZ8061: fix errata solution not taking effect problem

Message ID 1717119481-3353-1-git-send-email-Tristram.Ha@microchip.com (mailing list archive)
State Accepted
Commit 0a8d3f2e3e8d8aea8af017e14227b91d5989b696
Delegated to: Netdev Maintainers
Headers show
Series [v1,net] net: phy: Micrel KSZ8061: fix errata solution not taking effect problem | expand

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Context Check Description
netdev/series_format success Single patches do not need cover letters
netdev/tree_selection success Clearly marked for net
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag present in non-next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 902 this patch: 902
netdev/build_tools success No tools touched, skip
netdev/cc_maintainers success CCed 7 of 9 maintainers
netdev/build_clang success Errors and warnings before: 906 this patch: 906
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 Fixes tag looks correct
netdev/build_allmodconfig_warn success Errors and warnings before: 906 this patch: 906
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 60 lines checked
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0
netdev/contest success net-next-2024-06-03--15-00 (tests: 1041)

Commit Message

Tristram.Ha@microchip.com May 31, 2024, 1:38 a.m. UTC 
From: Tristram Ha <tristram.ha@microchip.com>

KSZ8061 needs to write to a MMD register at driver initialization to fix
an errata.  This worked in 5.0 kernel but not in newer kernels.  The
issue is the main phylib code no longer resets PHY at the very beginning.
Calling phy resuming code later will reset the chip if it is already
powered down at the beginning.  This wipes out the MMD register write.
Solution is to implement a phy resume function for KSZ8061 to take care
of this problem.

Fixes: 232ba3a51cc2 ("net: phy: Micrel KSZ8061: link failure after cable connect")
Signed-off-by: Tristram Ha <tristram.ha@microchip.com>
---
v1
 - Correct the kernel version to 5.0

 drivers/net/phy/micrel.c | 42 +++++++++++++++++++++++++++++++++++++++-
 1 file changed, 41 insertions(+), 1 deletion(-)

Comments

patchwork-bot+netdevbpf@kernel.org June 5, 2024, 9:10 a.m. UTC | #1 
Hello:

This patch was applied to netdev/net.git (main)
by David S. Miller <davem@davemloft.net>:

On Thu, 30 May 2024 18:38:01 -0700 you wrote:
> From: Tristram Ha <tristram.ha@microchip.com>
> 
> KSZ8061 needs to write to a MMD register at driver initialization to fix
> an errata.  This worked in 5.0 kernel but not in newer kernels.  The
> issue is the main phylib code no longer resets PHY at the very beginning.
> Calling phy resuming code later will reset the chip if it is already
> powered down at the beginning.  This wipes out the MMD register write.
> Solution is to implement a phy resume function for KSZ8061 to take care
> of this problem.
> 
> [...]

Here is the summary with links:
  - [v1,net] net: phy: Micrel KSZ8061: fix errata solution not taking effect problem
    https://git.kernel.org/netdev/net/c/0a8d3f2e3e8d

You are awesome, thank you!
diff mbox series

Patch

diff --git a/drivers/net/phy/micrel.c b/drivers/net/phy/micrel.c
index 2b8f8b7f1517..618e532ee5d7 100644
--- a/drivers/net/phy/micrel.c
+++ b/drivers/net/phy/micrel.c
@@ -866,6 +866,17 @@  static int ksz8061_config_init(struct phy_device *phydev)
 {
 	int ret;
 
+	/* Chip can be powered down by the bootstrap code. */
+	ret = phy_read(phydev, MII_BMCR);
+	if (ret < 0)
+		return ret;
+	if (ret & BMCR_PDOWN) {
+		ret = phy_write(phydev, MII_BMCR, ret & ~BMCR_PDOWN);
+		if (ret < 0)
+			return ret;
+		usleep_range(1000, 2000);
+	}
+
 	ret = phy_write_mmd(phydev, MDIO_MMD_PMAPMD, MDIO_DEVID1, 0xB61A);
 	if (ret)
 		return ret;
@@ -2085,6 +2096,35 @@  static int kszphy_resume(struct phy_device *phydev)
 	return 0;
 }
 
+static int ksz8061_resume(struct phy_device *phydev)
+{
+	int ret;
+
+	/* This function can be called twice when the Ethernet device is on. */
+	ret = phy_read(phydev, MII_BMCR);
+	if (ret < 0)
+		return ret;
+	if (!(ret & BMCR_PDOWN))
+		return 0;
+
+	genphy_resume(phydev);
+	usleep_range(1000, 2000);
+
+	/* Re-program the value after chip is reset. */
+	ret = phy_write_mmd(phydev, MDIO_MMD_PMAPMD, MDIO_DEVID1, 0xB61A);
+	if (ret)
+		return ret;
+
+	/* Enable PHY Interrupts */
+	if (phy_interrupt_is_valid(phydev)) {
+		phydev->interrupts = PHY_INTERRUPT_ENABLED;
+		if (phydev->drv->config_intr)
+			phydev->drv->config_intr(phydev);
+	}
+
+	return 0;
+}
+
 static int kszphy_probe(struct phy_device *phydev)
 {
 	const struct kszphy_type *type = phydev->drv->driver_data;
@@ -5339,7 +5379,7 @@  static struct phy_driver ksphy_driver[] = {
 	.config_intr	= kszphy_config_intr,
 	.handle_interrupt = kszphy_handle_interrupt,
 	.suspend	= kszphy_suspend,
-	.resume		= kszphy_resume,
+	.resume		= ksz8061_resume,
 }, {
 	.phy_id		= PHY_ID_KSZ9021,
 	.phy_id_mask	= 0x000ffffe,