linux-kernel - [RFC PATCH net-next 09/12] net: dsa: mt7530: move enabling port 6 to mt7530_setup

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20230405203859.391267-10-arinc.unal@arinc9.com>
Date:   Wed,  5 Apr 2023 23:38:56 +0300
From:   arinc9.unal@...il.com
To:     René van Dorst <opensource@...rst.com>,
        Sean Wang <sean.wang@...iatek.com>,
        Landen Chao <Landen.Chao@...iatek.com>,
        DENG Qingfang <dqfext@...il.com>,
        Daniel Golle <daniel@...rotopia.org>,
        Andrew Lunn <andrew@...n.ch>,
        Florian Fainelli <f.fainelli@...il.com>,
        Vladimir Oltean <olteanv@...il.com>,
        "David S. Miller" <davem@...emloft.net>,
        Eric Dumazet <edumazet@...gle.com>,
        Jakub Kicinski <kuba@...nel.org>,
        Paolo Abeni <pabeni@...hat.com>,
        Matthias Brugger <matthias.bgg@...il.com>,
        AngeloGioacchino Del Regno 
        <angelogioacchino.delregno@...labora.com>,
        Russell King <linux@...linux.org.uk>
Cc:     Arınç ÜNAL <arinc.unal@...nc9.com>,
        Ilya Lipnitskiy <ilya.lipnitskiy@...il.com>,
        Richard van Schagen <richard@...terhints.com>,
        Richard van Schagen <vschagen@...com>,
        Frank Wunderlich <frank-w@...lic-files.de>,
        erkin.bozoglu@...ont.com, netdev@...r.kernel.org,
        linux-kernel@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
        linux-mediatek@...ts.infradead.org
Subject: [RFC PATCH net-next 09/12] net: dsa: mt7530: move enabling port 6 to mt7530_setup_port6()

From: Arınç ÜNAL <arinc.unal@...nc9.com>

Enable port 6 only when port 6 is being used. Read the HWTRAP_XTAL_MASK
value from val now that val is equal to the value of MT7530_MHWTRAP.

Update the comment on mt7530_setup() with a better explanation.

Tested-by: Arınç ÜNAL <arinc.unal@...nc9.com>
Signed-off-by: Arınç ÜNAL <arinc.unal@...nc9.com>
---

Do I need to protect the register from being accessed by processes while
this operation is being done? I don't see this on mt7530_setup() but it's
being done on mt7530_setup_port5().

There's an oddity here. The XTAL mask is defined on the MT7530_HWTRAP
register, but it's being read from MT7530_MHWTRAP instead which is at a
different address.

HWTRAP_XTAL_MASK and reading HWTRAP_XTAL_MASK from MT7530_MHWTRAP was both
added with:

https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next.git/commit?id=7ef6f6f8d237fa6724108b57d9706cb5069688e4

I did this to test it:

diff --git a/drivers/net/dsa/mt7530.c b/drivers/net/dsa/mt7530.c
index 46749aee3c49..7aa3b5828ac3 100644
--- a/drivers/net/dsa/mt7530.c
+++ b/drivers/net/dsa/mt7530.c
@@ -404,7 +404,7 @@ static int
 mt7530_setup_port6(struct dsa_switch *ds, phy_interface_t interface)
 {
 	struct mt7530_priv *priv = ds->priv;
-	u32 ncpo1, ssc_delta, trgint, xtal, val;
+	u32 ncpo1, ssc_delta, trgint, xtal, xtal2, val;
 
 	/* Enable port 6 */
 	val = mt7530_read(priv, MT7530_MHWTRAP);
@@ -413,6 +413,21 @@ mt7530_setup_port6(struct dsa_switch *ds, phy_interface_t interface)
 	mt7530_write(priv, MT7530_MHWTRAP, val);
 
 	xtal = val & HWTRAP_XTAL_MASK;
+	xtal2 = mt7530_read(priv, MT7530_HWTRAP) & HWTRAP_XTAL_MASK;
+
+	if (xtal == HWTRAP_XTAL_20MHZ)
+		dev_info(priv->dev, "xtal 20 Mhz\n");
+	if (xtal == HWTRAP_XTAL_25MHZ)
+		dev_info(priv->dev, "xtal 25 Mhz\n");
+	if (xtal == HWTRAP_XTAL_40MHZ)
+		dev_info(priv->dev, "xtal 40 Mhz\n");
+
+	if (xtal2 == HWTRAP_XTAL_20MHZ)
+		dev_info(priv->dev, "actual xtal 20 Mhz\n");
+	if (xtal2 == HWTRAP_XTAL_25MHZ)
+		dev_info(priv->dev, "actual xtal 25 Mhz\n");
+	if (xtal2 == HWTRAP_XTAL_40MHZ)
+		dev_info(priv->dev, "actual xtal 40 Mhz\n");
 
 	if (xtal == HWTRAP_XTAL_20MHZ) {
 		dev_err(priv->dev,

Both ended up reporting 40 Mhz so I'm not sure if this is a bug or intended
to be done this way.

Please advise.

Arınç

---
 drivers/net/dsa/mt7530.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/drivers/net/dsa/mt7530.c b/drivers/net/dsa/mt7530.c
index 0a6d1c0872be..70a673347cf9 100644
--- a/drivers/net/dsa/mt7530.c
+++ b/drivers/net/dsa/mt7530.c
@@ -404,9 +404,13 @@ static int
 mt7530_setup_port6(struct dsa_switch *ds, phy_interface_t interface)
 {
 	struct mt7530_priv *priv = ds->priv;
-	u32 ncpo1, ssc_delta, trgint, xtal;
+	u32 ncpo1, ssc_delta, trgint, xtal, val;
 
-	xtal = mt7530_read(priv, MT7530_MHWTRAP) & HWTRAP_XTAL_MASK;
+	val = mt7530_read(priv, MT7530_MHWTRAP);
+	val &= ~MHWTRAP_P6_DIS;
+	mt7530_write(priv, MT7530_MHWTRAP, val);
+
+	xtal = val & HWTRAP_XTAL_MASK;
 
 	if (xtal == HWTRAP_XTAL_20MHZ) {
 		dev_err(priv->dev,
@@ -2235,9 +2239,9 @@ mt7530_setup(struct dsa_switch *ds)
 		mt7530_rmw(priv, MT7530_TRGMII_RD(i),
 			   RD_TAP_MASK, RD_TAP(16));
 
-	/* Enable port 6 */
+	/* Enable PHY access and operate in manual mode */
 	val = mt7530_read(priv, MT7530_MHWTRAP);
-	val &= ~MHWTRAP_P6_DIS & ~MHWTRAP_PHY_ACCESS;
+	val &= ~MHWTRAP_PHY_ACCESS;
 	val |= MHWTRAP_MANUAL;
 	mt7530_write(priv, MT7530_MHWTRAP, val);
 
-- 
2.37.2