From: Andrew Lunn <andrew@lunn.ch>
To: Ansuel Smith <ansuelsmth@gmail.com>
Cc: Florian Fainelli <f.fainelli@gmail.com>,
Vivien Didelot <vivien.didelot@gmail.com>,
Vladimir Oltean <olteanv@gmail.com>,
"David S. Miller" <davem@davemloft.net>,
Jakub Kicinski <kuba@kernel.org>,
Rob Herring <robh+dt@kernel.org>,
Heiner Kallweit <hkallweit1@gmail.com>,
Russell King <linux@armlinux.org.uk>,
netdev@vger.kernel.org, devicetree@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 03/14] drivers: net: mdio: mdio-ip8064: improve busy wait delay
Date: Fri, 23 Apr 2021 14:38:25 +0200 [thread overview]
Message-ID: <YIK/wUOplWbf4hK0@lunn.ch> (raw)
In-Reply-To: <20210423014741.11858-4-ansuelsmth@gmail.com>
On Fri, Apr 23, 2021 at 03:47:29AM +0200, Ansuel Smith wrote:
> With the use of the qca8k dsa driver, some problem arised related to
> port status detection. With a load on a specific port (for example a
> simple speed test), the driver starts to bheave in a strange way and
> garbage data is produced. To address this, enlarge the sleep delay and
> address a bug for the reg offset 31 that require additional delay for
> this specific reg.
> struct ipq8064_mdio {
> struct regmap *base; /* NSS_GMAC0_BASE */
> @@ -65,7 +66,7 @@ ipq8064_mdio_read(struct mii_bus *bus, int phy_addr, int reg_offset)
> ((reg_offset << MII_REG_SHIFT) & MII_REG_MASK);
>
> regmap_write(priv->base, MII_ADDR_REG_ADDR, miiaddr);
> - usleep_range(8, 10);
> + usleep_range(10, 13);
>
> err = ipq8064_mdio_wait_busy(priv);
> if (err)
> @@ -91,7 +92,14 @@ ipq8064_mdio_write(struct mii_bus *bus, int phy_addr, int reg_offset, u16 data)
> ((reg_offset << MII_REG_SHIFT) & MII_REG_MASK);
>
> regmap_write(priv->base, MII_ADDR_REG_ADDR, miiaddr);
> - usleep_range(8, 10);
> +
> + /* For the specific reg 31 extra time is needed or the next
> + * read will produce grabage data.
> + */
> + if (reg_offset == 31)
> + usleep_range(30, 43);
> + else
> + usleep_range(10, 13);
>
> return ipq8064_mdio_wait_busy(priv);
Is there any documentation as to what register 31 does?
Maybe the real problem is in ipq8064_mdio_wait_busy()? Have you looked
at how long you typically end up waiting? If you know the MDIO bus
speed, you can work out how long a transaction should take. If it is
taking less, something is broken.
Are you sure regmap caching is disabled, so that
ipq8064_mdio_wait_busy() really is reading the register, not some
old cached value?
Andrew
> }
> --
> 2.30.2
>
next prev parent reply other threads:[~2021-04-23 12:38 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-23 1:47 [PATCH 00/14] Multiple improvement to qca8k stability Ansuel Smith
2021-04-23 1:47 ` [PATCH 01/14] drivers: net: dsa: qca8k: handle error with set_page Ansuel Smith
2021-04-23 1:52 ` Florian Fainelli
2021-04-23 1:47 ` [PATCH 02/14] drivers: net: dsa: qca8k: tweak internal delay to oem spec Ansuel Smith
2021-04-23 1:53 ` Florian Fainelli
2021-04-23 1:57 ` Ansuel Smith
2021-04-23 1:58 ` Florian Fainelli
2021-04-23 12:25 ` Andrew Lunn
2021-04-23 1:47 ` [PATCH 03/14] drivers: net: mdio: mdio-ip8064: improve busy wait delay Ansuel Smith
2021-04-23 1:56 ` Florian Fainelli
2021-04-23 2:03 ` Ansuel Smith
2021-04-23 12:38 ` Andrew Lunn [this message]
2021-04-23 1:47 ` [PATCH 04/14] drivers: net: dsa: qca8k: apply suggested packet priority Ansuel Smith
2021-04-23 1:47 ` [PATCH 05/14] drivers: net: dsa: qca8k: add support for qca8327 switch Ansuel Smith
2021-04-23 12:42 ` Andrew Lunn
2021-04-23 1:47 ` [PATCH 06/14] devicetree: net: dsa: qca8k: Document new compatible qca8327 Ansuel Smith
2021-04-23 1:47 ` [PATCH 07/14] drivers: net: dsa: qca8k: limit priority tweak to qca8337 switch Ansuel Smith
2021-04-23 1:59 ` Florian Fainelli
2021-04-23 1:47 ` [PATCH 08/14] drivers: net: dsa: qca8k: add GLOBAL_FC settings needed for qca8327 Ansuel Smith
2021-04-23 1:47 ` [PATCH 09/14] drivers: net: dsa: qca8k: add support for switch rev Ansuel Smith
2021-04-23 1:47 ` [PATCH 10/14] drivers: net: dsa: qca8k: add support for specific QCA access function Ansuel Smith
2021-04-23 12:47 ` Andrew Lunn
2021-04-23 1:47 ` [PATCH 11/14] drivers: net: dsa: qca8k: apply switch revision fix Ansuel Smith
2021-04-23 2:02 ` Florian Fainelli
2021-04-24 21:18 ` Ansuel Smith
2021-04-24 21:49 ` Heiner Kallweit
2021-04-25 1:09 ` Florian Fainelli
2021-04-25 1:19 ` Ansuel Smith
2021-04-25 4:45 ` DENG Qingfang
2021-04-25 11:59 ` Ansuel Smith
2021-04-25 14:33 ` Andrew Lunn
2021-04-23 1:47 ` [PATCH 12/14] drivers: net: dsa: qca8k: clear MASTER_EN after phy read/write Ansuel Smith
2021-04-23 1:47 ` [PATCH 13/14] drivers: net: dsa: qca8k: protect MASTER busy_wait with mdio mutex Ansuel Smith
2021-04-23 12:53 ` Andrew Lunn
2021-04-23 1:47 ` [PATCH 14/14] drivers: net: dsa: qca8k: enlarge mdio delay and timeout Ansuel Smith
2021-04-23 1:51 ` [PATCH 00/14] Multiple improvement to qca8k stability Florian Fainelli
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