6.1-stable review patch. If anyone has any objections, please let me know.
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From: Pawel Dembicki paweldembicki@gmail.com
[ Upstream commit eb7e33d01db3aec128590391b2397384bab406b6 ]
Switch the delay loop during the Arbiter empty check from vsc73xx_adjust_link() to use read_poll_timeout(). Functionally, one msleep() call is eliminated at the end of the loop in the timeout case.
As Russell King suggested:
"This [change] avoids the issue that on the last iteration, the code reads the register, tests it, finds the condition that's being waiting for is false, _then_ waits and end up printing the error message - that last wait is rather useless, and as the arbiter state isn't checked after waiting, it could be that we had success during the last wait."
Suggested-by: Russell King linux@armlinux.org.uk Reviewed-by: Andrew Lunn andrew@lunn.ch Reviewed-by: Linus Walleij linus.walleij@linaro.org Reviewed-by: Florian Fainelli florian.fainelli@broadcom.com Signed-off-by: Pawel Dembicki paweldembicki@gmail.com Link: https://lore.kernel.org/r/20240417205048.3542839-2-paweldembicki@gmail.com Signed-off-by: Jakub Kicinski kuba@kernel.org Stable-dep-of: fa63c6434b6f ("net: dsa: vsc73xx: check busy flag in MDIO operations") Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/dsa/vitesse-vsc73xx-core.c | 30 ++++++++++++++------------ 1 file changed, 16 insertions(+), 14 deletions(-)
diff --git a/drivers/net/dsa/vitesse-vsc73xx-core.c b/drivers/net/dsa/vitesse-vsc73xx-core.c index 81d39dfe21f45..92087f9d73550 100644 --- a/drivers/net/dsa/vitesse-vsc73xx-core.c +++ b/drivers/net/dsa/vitesse-vsc73xx-core.c @@ -17,6 +17,7 @@ #include <linux/kernel.h> #include <linux/module.h> #include <linux/device.h> +#include <linux/iopoll.h> #include <linux/of.h> #include <linux/of_device.h> #include <linux/of_mdio.h> @@ -269,6 +270,9 @@ #define IS_7398(a) ((a)->chipid == VSC73XX_CHIPID_ID_7398) #define IS_739X(a) (IS_7395(a) || IS_7398(a))
+#define VSC73XX_POLL_SLEEP_US 1000 +#define VSC73XX_POLL_TIMEOUT_US 10000 + struct vsc73xx_counter { u8 counter; const char *name; @@ -780,7 +784,7 @@ static void vsc73xx_adjust_link(struct dsa_switch *ds, int port, * after a PHY or the CPU port comes up or down. */ if (!phydev->link) { - int maxloop = 10; + int ret, err;
dev_dbg(vsc->dev, "port %d: went down\n", port); @@ -795,19 +799,17 @@ static void vsc73xx_adjust_link(struct dsa_switch *ds, int port, VSC73XX_ARBDISC, BIT(port), BIT(port));
/* Wait until queue is empty */ - vsc73xx_read(vsc, VSC73XX_BLOCK_ARBITER, 0, - VSC73XX_ARBEMPTY, &val); - while (!(val & BIT(port))) { - msleep(1); - vsc73xx_read(vsc, VSC73XX_BLOCK_ARBITER, 0, - VSC73XX_ARBEMPTY, &val); - if (--maxloop == 0) { - dev_err(vsc->dev, - "timeout waiting for block arbiter\n"); - /* Continue anyway */ - break; - } - } + ret = read_poll_timeout(vsc73xx_read, err, + err < 0 || (val & BIT(port)), + VSC73XX_POLL_SLEEP_US, + VSC73XX_POLL_TIMEOUT_US, false, + vsc, VSC73XX_BLOCK_ARBITER, 0, + VSC73XX_ARBEMPTY, &val); + if (ret) + dev_err(vsc->dev, + "timeout waiting for block arbiter\n"); + else if (err < 0) + dev_err(vsc->dev, "error reading arbiter\n");
/* Put this port into reset */ vsc73xx_write(vsc, VSC73XX_BLOCK_MAC, port, VSC73XX_MAC_CFG,