[PATCH 5.15 073/148] net: phy: aquantia: wait for the suspend/resume operations to finish

Greg Kroah-Hartman
2022-09-26T11:21:35Z

From: Ioana Ciornei <ioana.ciornei@nxp.com>

[ Upstream commit ca2dccdeeb49a7e408112d681bf447984c845292 ]

The Aquantia datasheet notes that after issuing a Processor-Intensive
MDIO operation, like changing the low-power state of the device, the
driver should wait for the operation to finish before issuing a new MDIO
command.

The new aqr107_wait_processor_intensive_op() function is added which can
be used after these kind of MDIO operations. At the moment, we are only
adding it at the end of the suspend/resume calls.

The issue was identified on a board featuring the AQR113C PHY, on
which commands like 'ip link (..) up / down' issued without any delays
between them would render the link on the PHY to remain down.
The issue was easy to reproduce with a one-liner:
$ ip link set dev ethX down; ip link set dev ethX up; \
ip link set dev ethX down; ip link set dev ethX up;

Fixes: ac9e81c230eb ("net: phy: aquantia: add suspend / resume callbacks for AQR107 family")
Signed-off-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/20220906130451.1483448-1-ioana.ciornei@nxp.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/phy/aquantia_main.c | 53 ++++++++++++++++++++++++++++++---
1 file changed, 49 insertions(+), 4 deletions(-)

diff --git a/drivers/net/phy/aquantia_main.c b/drivers/net/phy/aquantia_main.c
index 3221224525ac..2f2765d7f84c 100644
--- a/drivers/net/phy/aquantia_main.c
+++ b/drivers/net/phy/aquantia_main.c
@@ -90,6 +90,9 @@
#define VEND1_GLOBAL_FW_ID_MAJOR GENMASK(15, 8)
#define VEND1_GLOBAL_FW_ID_MINOR GENMASK(7, 0)

+#define VEND1_GLOBAL_GEN_STAT2 0xc831
+#define VEND1_GLOBAL_GEN_STAT2_OP_IN_PROG BIT(15)
+
#define VEND1_GLOBAL_RSVD_STAT1 0xc885
#define VEND1_GLOBAL_RSVD_STAT1_FW_BUILD_ID GENMASK(7, 4)
#define VEND1_GLOBAL_RSVD_STAT1_PROV_ID GENMASK(3, 0)
@@ -124,6 +127,12 @@
#define VEND1_GLOBAL_INT_VEND_MASK_GLOBAL2 BIT(1)
#define VEND1_GLOBAL_INT_VEND_MASK_GLOBAL3 BIT(0)

+/* Sleep and timeout for checking if the Processor-Intensive
+ * MDIO operation is finished
+ */
+#define AQR107_OP_IN_PROG_SLEEP 1000
+#define AQR107_OP_IN_PROG_TIMEOUT 100000
+
struct aqr107_hw_stat {
const char *name;
int reg;
@@ -598,16 +607,52 @@ static void aqr107_link_change_notify(struct phy_device *phydev)
phydev_info(phydev, "Aquantia 1000Base-T2 mode active\n");
}

+static int aqr107_wait_processor_intensive_op(struct phy_device *phydev)
+{
+ int val, err;
+
+ /* The datasheet notes to wait at least 1ms after issuing a
+ * processor intensive operation before checking.
+ * We cannot use the 'sleep_before_read' parameter of read_poll_timeout
+ * because that just determines the maximum time slept, not the minimum.
+ */
+ usleep_range(1000, 5000);
+
+ err = phy_read_mmd_poll_timeout(phydev, MDIO_MMD_VEND1,
+ VEND1_GLOBAL_GEN_STAT2, val,
+ !(val & VEND1_GLOBAL_GEN_STAT2_OP_IN_PROG),
+ AQR107_OP_IN_PROG_SLEEP,
+ AQR107_OP_IN_PROG_TIMEOUT, false);
+ if (err) {
+ phydev_err(phydev, "timeout: processor-intensive MDIO operation\n");
+ return err;
+ }
+
+ return 0;
+}
+
static int aqr107_suspend(struct phy_device *phydev)
{
- return phy_set_bits_mmd(phydev, MDIO_MMD_VEND1, MDIO_CTRL1,
- MDIO_CTRL1_LPOWER);
+ int err;
+
+ err = phy_set_bits_mmd(phydev, MDIO_MMD_VEND1, MDIO_CTRL1,
+ MDIO_CTRL1_LPOWER);
+ if (err)
+ return err;
+
+ return aqr107_wait_processor_intensive_op(phydev);
}

static int aqr107_resume(struct phy_device *phydev)
{
- return phy_clear_bits_mmd(phydev, MDIO_MMD_VEND1, MDIO_CTRL1,
- MDIO_CTRL1_LPOWER);
+ int err;
+
+ err = phy_clear_bits_mmd(phydev, MDIO_MMD_VEND1, MDIO_CTRL1,
+ MDIO_CTRL1_LPOWER);
+ if (err)
+ return err;
+
+ return aqr107_wait_processor_intensive_op(phydev);
}

static int aqr107_probe(struct phy_device *phydev)
--
2.35.1