Messages in this thread Patch in this message | | | From | Pawel Dembicki <> | Subject | [PATCH net-next v8 01/16] net: dsa: vsc73xx: use read_poll_timeout instead delay loop | Date | Wed, 3 Apr 2024 12:37:17 +0200 |
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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> --- v8,v7,v6: - resend only v5: - improved commit description - added two defines instead magic numbers - added include with iopoll.h v4: - resend patch v3: - added "Reviewed-by" to commit message only v2: - introduced patch
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 ae70eac3be28..ab5771d4d828 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_mdio.h> #include <linux/bitops.h> @@ -268,6 +269,9 @@ #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; @@ -779,7 +783,7 @@ 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); @@ -794,19 +798,17 @@ 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, -- 2.34.1
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