RE: [PATCH v3] net: stmmac: fix maxmtu assignment to be within valid range

-----Original Message-----
From: Joao Pinto [mailto:Joao.Pinto@synopsys.com]
Sent: Saturday, January 07, 2017 12:58 AM
To: Kweh, Hock Leong <redacted>; David S. Miller
[off-list ref]; Joao Pinto [off-list ref]; Giuseppe
CAVALLARO [off-list ref]; seraphin.bonnaffe@st.com; Jarod
Wilson [off-list ref]; Andy Shevchenko [off-list ref]
Cc: Alexandre TORGUE <redacted>; Joachim Eastwood
[off-list ref]; Niklas Cassel [off-list ref]; Johan Hovold
[off-list ref]; pavel@ucw.cz; lars.persson@axis.com; netdev
[off-list ref]; LKML [off-list ref]
Subject: Re: [PATCH v3] net: stmmac: fix maxmtu assignment to be within valid
range


Hi Wilson,

Às 12:49 AM de 1/7/2017, Kweh, Hock Leong escreveu:

quoted

From: "Kweh, Hock Leong" <redacted>

There is no checking valid value of maxmtu when getting it from device tree.
This resolution added the checking condition to ensure the assignment is
made within a valid range.

Signed-off-by: Kweh, Hock Leong <redacted>
---
changelog v3:
* print the warning message only if maxmtu < min_mtu
* add maxmtu = JUMBO_LEN at stmmac_pci.c to follow stmmac_platform.c

changelog v2:
* correction of "devicetree" to "device tree" reported by Andy
* print warning message while maxmtu is not in valid range

 drivers/net/ethernet/stmicro/stmmac/stmmac_main.c |    8 +++++++-
 drivers/net/ethernet/stmicro/stmmac/stmmac_pci.c  |    4 ++++
 2 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c

b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c

quoted

index 92ac006..ce74ae6 100644

--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c

@@ -3345,8 +3345,14 @@ int stmmac_dvr_probe(struct device *device,
 		ndev->max_mtu = JUMBO_LEN;
 	else
 		ndev->max_mtu = SKB_MAX_HEAD(NET_SKB_PAD +

NET_IP_ALIGN);

quoted

-	if (priv->plat->maxmtu < ndev->max_mtu)
+
+	if ((priv->plat->maxmtu < ndev->max_mtu) &&
+	    (priv->plat->maxmtu >= ndev->min_mtu))
 		ndev->max_mtu = priv->plat->maxmtu;
+	else if (priv->plat->maxmtu < ndev->min_mtu)
+		netdev_warn(priv->dev,
+			    "%s: warning: maxmtu having invalid value (%d)\n",
+			    __func__, priv->plat->maxmtu);

 	if (flow_ctrl)
 		priv->flow_ctrl = FLOW_AUTO;	/* RX/TX pause on */

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_pci.c

b/drivers/net/ethernet/stmicro/stmmac/stmmac_pci.c

quoted

index a283177..e539afe 100644

--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_pci.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_pci.c

@@ -204,6 +204,10 @@ static int stmmac_pci_probe(struct pci_dev *pdev,

 	pci_set_master(pdev);

+	/* Set the maxmtu to a default of JUMBO_LEN in case the
+	 * parameter is not defined for the device.
+	 */
+	plat->maxmtu = JUMBO_LEN;

I suggest to put this configuration in one of the default config functions.

Tahnks.

My original thought is to have one line for all *_default_data() instead of having
multiple same line inside each *_default_data(). If this is not a big concern of
future expand, I can do that. Thanks.

quoted

 	if (info) {
 		info->pdev = pdev;
 		if (info->setup) {