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net: dsa: vsc73xx: use read_poll_timeout instead delay loop

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[ 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>
This commit is contained in:
Pawel Dembicki 2024-04-17 22:50:44 +02:00 • committed by Ksawlii
parent 3c0fd5c577
commit 98c55bf660
1 changed files with 16 additions and 14 deletions
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30
drivers/net/dsa/vitesse-vsc73xx-core.c
View file

@ -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,