[net-next,v2,1/7] net: dsa: vsc73xx: use read_poll_timeout instead delay loop
Commit Message
This commit switches delay loop to read_poll_timeout macro durring
Arbiter empty check in adjust link function.
As Russel King suggested:
"This [change] avoids the issue that on the last iteration, the code reads
the register, test it, find 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."
It also remove one short msleep delay.
Suggested-by: Russell King <linux@armlinux.org.uk>
Signed-off-by: Pawel Dembicki <paweldembicki@gmail.com>
---
v2:
- introduced patch
drivers/net/dsa/vitesse-vsc73xx-core.c | 25 +++++++++++--------------
1 file changed, 11 insertions(+), 14 deletions(-)
Comments
On Sun, Jun 25, 2023 at 01:53:36PM +0200, Pawel Dembicki wrote:
> This commit switches delay loop to read_poll_timeout macro durring
> Arbiter empty check in adjust link function.
>
> As Russel King suggested:
>
> "This [change] avoids the issue that on the last iteration, the code reads
> the register, test it, find 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."
>
> It also remove one short msleep delay.
>
> Suggested-by: Russell King <linux@armlinux.org.uk>
> Signed-off-by: Pawel Dembicki <paweldembicki@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Andrew
@@ -780,7 +780,7 @@ 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 +795,16 @@ 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)),
+ 1000, 10000, 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,