[PATCH net-next v6 04/25] net: dsa: qca8k: handle qca8k_set_page errors

Ansuel Smith
2021-05-14T21:00:41Z

With a remote possibility, the set_page function can fail. Since this is
a critical part of the write/read qca8k regs, propagate the error and
terminate any read/write operation.

Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
---
drivers/net/dsa/qca8k.c | 33 ++++++++++++++++++++++++++-------
1 file changed, 26 insertions(+), 7 deletions(-)

diff --git a/drivers/net/dsa/qca8k.c b/drivers/net/dsa/qca8k.c
index 3c882d325fdf..c9830286fd6d 100644
--- a/drivers/net/dsa/qca8k.c
+++ b/drivers/net/dsa/qca8k.c
@@ -127,16 +127,23 @@ qca8k_mii_write32(struct mii_bus *bus, int phy_id, u32 regnum, u32 val)
"failed to write qca8k 32bit register\n");
}

-static void
+static int
qca8k_set_page(struct mii_bus *bus, u16 page)
{
+ int ret;
+
if (page == qca8k_current_page)
- return;
+ return 0;

- if (bus->write(bus, 0x18, 0, page) < 0)
+ ret = bus->write(bus, 0x18, 0, page);
+ if (ret < 0) {
dev_err_ratelimited(&bus->dev,
"failed to set qca8k page\n");
+ return ret;
+ }
+
qca8k_current_page = page;
+ return 0;
}

static u32
@@ -150,11 +157,14 @@ qca8k_read(struct qca8k_priv *priv, u32 reg)

mutex_lock_nested(&bus->mdio_lock, MDIO_MUTEX_NESTED);

- qca8k_set_page(bus, page);
+ val = qca8k_set_page(bus, page);
+ if (val < 0)
+ goto exit;
+
val = qca8k_mii_read32(bus, 0x10 | r2, r1);

+exit:
mutex_unlock(&bus->mdio_lock);
-
return val;
}

@@ -163,14 +173,19 @@ qca8k_write(struct qca8k_priv *priv, u32 reg, u32 val)
{
struct mii_bus *bus = priv->bus;
u16 r1, r2, page;
+ int ret;

qca8k_split_addr(reg, &r1, &r2, &page);

mutex_lock_nested(&bus->mdio_lock, MDIO_MUTEX_NESTED);

- qca8k_set_page(bus, page);
+ ret = qca8k_set_page(bus, page);
+ if (ret < 0)
+ goto exit;
+
qca8k_mii_write32(bus, 0x10 | r2, r1, val);

+exit:
mutex_unlock(&bus->mdio_lock);
}

@@ -185,12 +200,16 @@ qca8k_rmw(struct qca8k_priv *priv, u32 reg, u32 mask, u32 val)

mutex_lock_nested(&bus->mdio_lock, MDIO_MUTEX_NESTED);

- qca8k_set_page(bus, page);
+ ret = qca8k_set_page(bus, page);
+ if (ret < 0)
+ goto exit;
+
ret = qca8k_mii_read32(bus, 0x10 | r2, r1);
ret &= ~mask;
ret |= val;
qca8k_mii_write32(bus, 0x10 | r2, r1, ret);

+exit:
mutex_unlock(&bus->mdio_lock);

return ret;
--
2.30.2