[PATCH net v2] net: phy: mxl-gpy: fix delay time required by loopback disable function

[PATCH net v2] net: phy: mxl-gpy: fix delay time required by loopback disable function

[Xu Liang]

GPY2xx devices need 3 seconds to fully switch out of loopback mode
before it can safely re-enter loopback mode.

Signed-off-by: Xu Liang <lxu@maxlinear.com>
---
 drivers/net/phy/mxl-gpy.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/net/phy/mxl-gpy.c b/drivers/net/phy/mxl-gpy.c
index 147d7a5a9b35..b682d7fc477c 100644
--- a/drivers/net/phy/mxl-gpy.c
+++ b/drivers/net/phy/mxl-gpy.c
@@ -770,9 +770,11 @@ static int gpy_loopback(struct phy_device *phydev, bool enable)
 			 enable ? BMCR_LOOPBACK : 0);
 	if (!ret) {
 		/* It takes some time for PHY device to switch
-		 * into/out-of loopback mode.
+		 * into/out-of loopback mode. It takes 3 seconds
+		 * to fully switch out of loopback mode before
+		 * it can safely re-enter loopback mode.
 		 */
-		msleep(100);
+		msleep(enable ? 100 : 3000);
 	}
 
 	return ret;
-- 
2.17.1

Re: [PATCH net v2] net: phy: mxl-gpy: fix delay time required by loopback disable function

[Russell King (Oracle)]

Hi,

On Wed, Dec 21, 2022 at 05:43:58PM +0800, Xu Liang wrote:
> GPY2xx devices need 3 seconds to fully switch out of loopback mode
> before it can safely re-enter loopback mode.

Would it be better to record the time that loopback mode is exited,
and then delay an attempt to re-enter loopback mode if it's less than
three seconds since we exited?

Thanks.

-- 
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
FTTP is here! 40Mbps down 10Mbps up. Decent connectivity at last!

Re: [PATCH net v2] net: phy: mxl-gpy: fix delay time required by loopback disable function

[Liang Xu]

Thanks & Regards,
Xu Liang

> ________________________________________
> From: Russell King <linux@armlinux.org.uk> on behalf of Russell King (Oracle) <linux@armlinux.org.uk>
> Sent: Wednesday, December 21, 2022 8:21 PM
> To: Liang Xu
> Cc: andrew@lunn.ch; hkallweit1@gmail.com; netdev@vger.kernel.org; davem@davemloft.net; kuba@kernel.org; Hauke Mehrtens; Thomas Mohren; Ismail, Mohammad Athari; edumazet@google.com; pabeni@redhat.com
> Subject: Re: [PATCH net v2] net: phy: mxl-gpy: fix delay time required by loopback disable function
> 
> This email was sent from outside of MaxLinear.
> 
> Hi,
> 
> On Wed, Dec 21, 2022 at 05:43:58PM +0800, Xu Liang wrote:
> > GPY2xx devices need 3 seconds to fully switch out of loopback mode
> > before it can safely re-enter loopback mode.
> 
> Would it be better to record the time that loopback mode is exited,
> and then delay an attempt to re-enter loopback mode if it's less than
> three seconds since we exited?

Loopback is usually used in self-test or debugging.
So I just made a simple delay to avoid complexity of time recording.
Please let me know if you think it's worth to change, then I will update the patch.

> 
> Thanks.
> 
> --
> RMK's Patch system: https://www.armlinux.org.uk/developer/patches/<https://www.armlinux.org.uk/developer/patches>
> FTTP is here! 40Mbps down 10Mbps up. Decent connectivity at last!
> 

Re: [PATCH net v2] net: phy: mxl-gpy: fix delay time required by loopback disable function

[Michael Walle]

Hi,

> GPY2xx devices need 3 seconds to fully switch out of loopback mode
> before it can safely re-enter loopback mode.
> 
> Signed-off-by: Xu Liang <lxu@maxlinear.com>

Again, no Fixes tag?

Changelog is missing, what has changes since v1? Also it is good
practice to CC the ones which made comments on the previous versions.

-michael