The issue happened randomly in runtime. The message "Link is Down" is
popped but soon it recovered to "Link is Up".
The "Link is Down" results from the incorrect read data for reading the
PHY register via MDIO bus. The correct sequence for reading the data
shall be:
1. fire the command
2. wait for command done (this step was missing)
3. wait for data idle
4. read data from data register
Fixes: a9770eac511a ("net: mdio: Move MDIO drivers into a new subdirectory")
Signed-off-by: Dylan Hung <[email protected]>
---
drivers/net/mdio/mdio-aspeed.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/drivers/net/mdio/mdio-aspeed.c b/drivers/net/mdio/mdio-aspeed.c
index cad820568f75..966c3b4ad59d 100644
--- a/drivers/net/mdio/mdio-aspeed.c
+++ b/drivers/net/mdio/mdio-aspeed.c
@@ -61,6 +61,13 @@ static int aspeed_mdio_read(struct mii_bus *bus, int addr, int regnum)
iowrite32(ctrl, ctx->base + ASPEED_MDIO_CTRL);
+ rc = readl_poll_timeout(ctx->base + ASPEED_MDIO_CTRL, ctrl,
+ !(ctrl & ASPEED_MDIO_CTRL_FIRE),
+ ASPEED_MDIO_INTERVAL_US,
+ ASPEED_MDIO_TIMEOUT_US);
+ if (rc < 0)
+ return rc;
+
rc = readl_poll_timeout(ctx->base + ASPEED_MDIO_DATA, data,
data & ASPEED_MDIO_DATA_IDLE,
ASPEED_MDIO_INTERVAL_US,
--
2.25.1
On Wed, 24 Nov 2021 at 06:11, Dylan Hung <[email protected]> wrote:
>
> The issue happened randomly in runtime. The message "Link is Down" is
> popped but soon it recovered to "Link is Up".
>
> The "Link is Down" results from the incorrect read data for reading the
> PHY register via MDIO bus. The correct sequence for reading the data
> shall be:
> 1. fire the command
> 2. wait for command done (this step was missing)
> 3. wait for data idle
> 4. read data from data register
I consulted the datasheet and it doesn't mention this. Perhaps
something to be added?
Reviewed-by: Joel Stanley <[email protected]>
>
> Fixes: a9770eac511a ("net: mdio: Move MDIO drivers into a new subdirectory")
I think this should be:
Fixes: f160e99462c6 ("net: phy: Add mdio-aspeed")
We should cc stable too.
> Signed-off-by: Dylan Hung <[email protected]>
> ---
> drivers/net/mdio/mdio-aspeed.c | 7 +++++++
> 1 file changed, 7 insertions(+)
>
> diff --git a/drivers/net/mdio/mdio-aspeed.c b/drivers/net/mdio/mdio-aspeed.c
> index cad820568f75..966c3b4ad59d 100644
> --- a/drivers/net/mdio/mdio-aspeed.c
> +++ b/drivers/net/mdio/mdio-aspeed.c
> @@ -61,6 +61,13 @@ static int aspeed_mdio_read(struct mii_bus *bus, int addr, int regnum)
>
> iowrite32(ctrl, ctx->base + ASPEED_MDIO_CTRL);
>
> + rc = readl_poll_timeout(ctx->base + ASPEED_MDIO_CTRL, ctrl,
> + !(ctrl & ASPEED_MDIO_CTRL_FIRE),
> + ASPEED_MDIO_INTERVAL_US,
> + ASPEED_MDIO_TIMEOUT_US);
> + if (rc < 0)
> + return rc;
> +
> rc = readl_poll_timeout(ctx->base + ASPEED_MDIO_DATA, data,
> data & ASPEED_MDIO_DATA_IDLE,
> ASPEED_MDIO_INTERVAL_US,
> --
> 2.25.1
>
> -----Original Message-----
> From: Joel Stanley [mailto:[email protected]]
> Sent: 2021年11月24日 6:06 PM
> To: Dylan Hung <[email protected]>
> Cc: Linux Kernel Mailing List <[email protected]>; linux-aspeed
> <[email protected]>; Linux ARM
> <[email protected]>; Networking
> <[email protected]>; Andrew Jeffery <[email protected]>; Jakub Kicinski
> <[email protected]>; David S . Miller <[email protected]>; Russell King
> <[email protected]>; [email protected]; Andrew Lunn
> <[email protected]>; BMC-SW <[email protected]>
> Subject: Re: [PATCH] net:phy: Fix "Link is Down" issue
>
> On Wed, 24 Nov 2021 at 06:11, Dylan Hung <[email protected]>
> wrote:
> >
> > The issue happened randomly in runtime. The message "Link is Down" is
> > popped but soon it recovered to "Link is Up".
> >
> > The "Link is Down" results from the incorrect read data for reading
> > the PHY register via MDIO bus. The correct sequence for reading the
> > data shall be:
> > 1. fire the command
> > 2. wait for command done (this step was missing) 3. wait for data idle
> > 4. read data from data register
>
> I consulted the datasheet and it doesn't mention this. Perhaps something to be
> added?
We will add this sequence into the datasheet, thank you.
>
> Reviewed-by: Joel Stanley <[email protected]>
>
> >
> > Fixes: a9770eac511a ("net: mdio: Move MDIO drivers into a new
> > subdirectory")
>
> I think this should be:
>
> Fixes: f160e99462c6 ("net: phy: Add mdio-aspeed")
I will change this in V2.
>
> We should cc stable too.
I will change this in V2.
>
> > Signed-off-by: Dylan Hung <[email protected]>
> > ---
> > drivers/net/mdio/mdio-aspeed.c | 7 +++++++
> > 1 file changed, 7 insertions(+)
> >
> > diff --git a/drivers/net/mdio/mdio-aspeed.c
> > b/drivers/net/mdio/mdio-aspeed.c index cad820568f75..966c3b4ad59d
> > 100644
> > --- a/drivers/net/mdio/mdio-aspeed.c
> > +++ b/drivers/net/mdio/mdio-aspeed.c
> > @@ -61,6 +61,13 @@ static int aspeed_mdio_read(struct mii_bus *bus,
> > int addr, int regnum)
> >
> > iowrite32(ctrl, ctx->base + ASPEED_MDIO_CTRL);
> >
> > + rc = readl_poll_timeout(ctx->base + ASPEED_MDIO_CTRL, ctrl,
> > + !(ctrl & ASPEED_MDIO_CTRL_FIRE),
> > + ASPEED_MDIO_INTERVAL_US,
> > + ASPEED_MDIO_TIMEOUT_US);
> > + if (rc < 0)
> > + return rc;
> > +
> > rc = readl_poll_timeout(ctx->base + ASPEED_MDIO_DATA, data,
> > data & ASPEED_MDIO_DATA_IDLE,
> > ASPEED_MDIO_INTERVAL_US,
> > --
> > 2.25.1
> >
> We should cc stable too.
https://www.kernel.org/doc/html/v5.12/networking/netdev-FAQ.html#how-do-i-indicate-which-tree-net-vs-net-next-my-patch-should-be-in
Andrew
On Wed, 24 Nov 2021 14:10:57 +0800 Dylan Hung wrote:
> Subject: [PATCH] net:phy: Fix "Link is Down" issue
Since there will be v2, please also add a space between net: and phy:.
> -----Original Message-----
> From: Jakub Kicinski [mailto:[email protected]]
> Sent: 2021?~11??25?? 7:31 AM
> To: Dylan Hung <[email protected]>
> Cc: [email protected]; [email protected];
> [email protected]; [email protected];
> [email protected]; [email protected]; [email protected];
> [email protected]; [email protected]; [email protected]; BMC-SW
> <[email protected]>
> Subject: Re: [PATCH] net:phy: Fix "Link is Down" issue
>
> On Wed, 24 Nov 2021 14:10:57 +0800 Dylan Hung wrote:
> > Subject: [PATCH] net:phy: Fix "Link is Down" issue
>
> Since there will be v2, please also add a space between net: and phy:.
Should I use "net: mdio: " instead of "net: phy: "? Since this file was moved from net/phy to net/mdio by commit a9770eac511a.
> -----Original Message-----
> From: Andrew Lunn [mailto:[email protected]]
> Sent: 2021?~11??24?? 11:30 PM
> To: Joel Stanley <[email protected]>
> Cc: Dylan Hung <[email protected]>; Linux Kernel Mailing List
> <[email protected]>; linux-aspeed <[email protected]>;
> Linux ARM <[email protected]>; Networking
> <[email protected]>; Andrew Jeffery <[email protected]>; Jakub Kicinski
> <[email protected]>; David S . Miller <[email protected]>; Russell King
> <[email protected]>; [email protected]; BMC-SW
> <[email protected]>
> Subject: Re: [PATCH] net:phy: Fix "Link is Down" issue
>
> > We should cc stable too.
>
> https://www.kernel.org/doc/html/v5.12/networking/netdev-FAQ.html#how-do-
> i-indicate-which-tree-net-vs-net-next-my-patch-should-be-in
>
> Andrew
Sorry, I got this mail after I sent v2 out. Should I prepare patch v3 with --subject-prefix='PATCH net'?
On Thu, 25 Nov 2021 03:08:22 +0000 Dylan Hung wrote:
> > > We should cc stable too.
> >
> > https://www.kernel.org/doc/html/v5.12/networking/netdev-FAQ.html#how-do-
> > i-indicate-which-tree-net-vs-net-next-my-patch-should-be-in
>
> Sorry, I got this mail after I sent v2 out. Should I prepare patch
> v3 with --subject-prefix='PATCH net'?
That's leave it be now, but please keep this in mind in the future.