Re: [PATCH net] net: dsa: felix: ignore pending status of TAS module when it's disabled

Re: [PATCH net] net: dsa: felix: ignore pending status of TAS module when it's disabled

[Vladimir Oltean]

Hi Xiaoliang,

On Wed, Sep 04, 2024 at 06:27:22PM +0800, Xiaoliang Yang wrote:
> The TAS module could not be configured when it's running in pending
> status. We need disable the module and configure it again. However, the
> pending status is not cleared after the module disabled. So we don't
> need to check the pending status if TAS module is disabled.
> 
> Signed-off-by: Xiaoliang Yang <xiaoliang.yang_1@nxp.com>
> ---

Does this fix a functional, user-visible problem? If so, which problem is that?
Could you describe it in the commit message? And maybe add a Fixes: tag
to the patch where the problem was first visible?

[PATCH net] net: dsa: felix: ignore pending status of TAS module when it's disabled

[Xiaoliang Yang]

The TAS module could not be configured when it's running in pending
status. We need disable the module and configure it again. However, the
pending status is not cleared after the module disabled. So we don't
need to check the pending status if TAS module is disabled.

Signed-off-by: Xiaoliang Yang <xiaoliang.yang_1@nxp.com>
---
 drivers/net/dsa/ocelot/felix_vsc9959.c | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/drivers/net/dsa/ocelot/felix_vsc9959.c b/drivers/net/dsa/ocelot/felix_vsc9959.c
index ba37a566da39..ecfa73725d25 100644
--- a/drivers/net/dsa/ocelot/felix_vsc9959.c
+++ b/drivers/net/dsa/ocelot/felix_vsc9959.c
@@ -1474,10 +1474,13 @@ static int vsc9959_qos_port_tas_set(struct ocelot *ocelot, int port,
 	/* Hardware errata -  Admin config could not be overwritten if
 	 * config is pending, need reset the TAS module
 	 */
-	val = ocelot_read(ocelot, QSYS_PARAM_STATUS_REG_8);
-	if (val & QSYS_PARAM_STATUS_REG_8_CONFIG_PENDING) {
-		ret = -EBUSY;
-		goto err_reset_tc;
+	val = ocelot_read_rix(ocelot, QSYS_TAG_CONFIG, port);
+	if (val & QSYS_TAG_CONFIG_ENABLE) {
+		val = ocelot_read(ocelot, QSYS_PARAM_STATUS_REG_8);
+		if (val & QSYS_PARAM_STATUS_REG_8_CONFIG_PENDING) {
+			ret = -EBUSY;
+			goto err_reset_tc;
+		}
 	}
 
 	ocelot_rmw_rix(ocelot,
-- 
2.17.1

RE: [PATCH net] net: dsa: felix: ignore pending status of TAS module when it's disabled

[Xiaoliang Yang]

Hi Vladimir,

Yes, it's a user-visible problem. User can't reconfigured Qbv once the TAS is 
in pending status(configured the Qbv basetime as a future time). The driver 
always returns busy. Actually Qbv can be reconfigured after it's disabled. 
I update the commit to descript it and send in a new patch.

Thanks,
Xiaoliang

> -----Original Message-----
> From: Vladimir Oltean <vladimir.oltean@nxp.com>
> Sent: Wednesday, September 4, 2024 6:12 PM
> To: Xiaoliang Yang <xiaoliang.yang_1@nxp.com>
> Cc: netdev@vger.kernel.org; davem@davemloft.net; kuba@kernel.org;
> pabeni@redhat.com; Claudiu Manoil <claudiu.manoil@nxp.com>;
> alexandre.belloni@bootlin.com; UNGLinuxDriver@microchip.com;
> andrew@lunn.ch; f.fainelli@gmail.com; michael@walle.cc;
> linux-kernel@vger.kernel.org
> Subject: Re: [PATCH net] net: dsa: felix: ignore pending status of TAS module
> when it's disabled
> 
> Hi Xiaoliang,
> 
> On Wed, Sep 04, 2024 at 06:27:22PM +0800, Xiaoliang Yang wrote:
> > The TAS module could not be configured when it's running in pending
> > status. We need disable the module and configure it again. However,
> > the pending status is not cleared after the module disabled. So we
> > don't need to check the pending status if TAS module is disabled.
> >
> > Signed-off-by: Xiaoliang Yang <xiaoliang.yang_1@nxp.com>
> > ---
> 
> Does this fix a functional, user-visible problem? If so, which problem is that?
> Could you describe it in the commit message? And maybe add a Fixes: tag to
> the patch where the problem was first visible?