From: Shravya Kumbham <[email protected]>
Add ret variable, conditions to check the return value and it's error
path for of_address_to_resource() and phy_read() functions.
Addresses-Coverity: Event check_return value.
Signed-off-by: Shravya Kumbham <[email protected]>
Signed-off-by: Radhey Shyam Pandey <[email protected]>
---
drivers/net/ethernet/xilinx/xilinx_emaclite.c | 19 ++++++++++++++++---
1 file changed, 16 insertions(+), 3 deletions(-)
diff --git a/drivers/net/ethernet/xilinx/xilinx_emaclite.c b/drivers/net/ethernet/xilinx/xilinx_emaclite.c
index 0c26f5b..fc5ccd1 100644
--- a/drivers/net/ethernet/xilinx/xilinx_emaclite.c
+++ b/drivers/net/ethernet/xilinx/xilinx_emaclite.c
@@ -820,7 +820,7 @@ static int xemaclite_mdio_write(struct mii_bus *bus, int phy_id, int reg,
static int xemaclite_mdio_setup(struct net_local *lp, struct device *dev)
{
struct mii_bus *bus;
- int rc;
+ int rc, ret;
struct resource res;
struct device_node *np = of_get_parent(lp->phy_node);
struct device_node *npp;
@@ -834,7 +834,13 @@ static int xemaclite_mdio_setup(struct net_local *lp, struct device *dev)
}
npp = of_get_parent(np);
- of_address_to_resource(npp, 0, &res);
+ ret = of_address_to_resource(npp, 0, &res);
+ if (ret) {
+ dev_err(dev, "%s resource error!\n",
+ dev->of_node->full_name);
+ of_node_put(lp->phy_node);
+ return ret;
+ }
if (lp->ndev->mem_start != res.start) {
struct phy_device *phydev;
phydev = of_phy_find_device(lp->phy_node);
@@ -923,7 +929,7 @@ static int xemaclite_open(struct net_device *dev)
xemaclite_disable_interrupts(lp);
if (lp->phy_node) {
- u32 bmcr;
+ int bmcr;
lp->phy_dev = of_phy_connect(lp->ndev, lp->phy_node,
xemaclite_adjust_link, 0,
@@ -945,6 +951,13 @@ static int xemaclite_open(struct net_device *dev)
/* Restart auto negotiation */
bmcr = phy_read(lp->phy_dev, MII_BMCR);
+ if (bmcr < 0) {
+ dev_err(&lp->ndev->dev, "phy_read failed\n");
+ phy_disconnect(lp->phy_dev);
+ lp->phy_dev = NULL;
+
+ return bmcr;
+ }
bmcr |= (BMCR_ANENABLE | BMCR_ANRESTART);
phy_write(lp->phy_dev, MII_BMCR, bmcr);
--
2.7.4
On Tue, Nov 03, 2020 at 07:01:05PM +0530, Radhey Shyam Pandey wrote:
> From: Shravya Kumbham <[email protected]>
>
> Add ret variable, conditions to check the return value and it's error
> path for of_address_to_resource() and phy_read() functions.
>
> Addresses-Coverity: Event check_return value.
Hi Radhey
This is well out of scope of a Coverity fix, but looking at the patch
i noticed some bad things.
> @@ -923,7 +929,7 @@ static int xemaclite_open(struct net_device *dev)
> xemaclite_disable_interrupts(lp);
>
> if (lp->phy_node) {
> - u32 bmcr;
> + int bmcr;
>
> lp->phy_dev = of_phy_connect(lp->ndev, lp->phy_node,
> xemaclite_adjust_link, 0,
> @@ -945,6 +951,13 @@ static int xemaclite_open(struct net_device *dev)
>
> /* Restart auto negotiation */
> bmcr = phy_read(lp->phy_dev, MII_BMCR);
> + if (bmcr < 0) {
> + dev_err(&lp->ndev->dev, "phy_read failed\n");
> + phy_disconnect(lp->phy_dev);
> + lp->phy_dev = NULL;
> +
> + return bmcr;
> + }
> bmcr |= (BMCR_ANENABLE | BMCR_ANRESTART);
> phy_write(lp->phy_dev, MII_BMCR, bmcr);
A MAC driver should not be touching the PHY. The call to
phy_set_max_speed() should prevent the PHY from advertising 1G speeds,
so there is no need to poke the advertise registers. And phy_start()
will start auto-get if it is enabled.
It would be nice if this code got cleaned up.
Andrew
On Tue, 3 Nov 2020 19:01:05 +0530 Radhey Shyam Pandey wrote:
> From: Shravya Kumbham <[email protected]>
>
> Add ret variable, conditions to check the return value and it's error
> path for of_address_to_resource() and phy_read() functions.
>
> Addresses-Coverity: Event check_return value.
> Signed-off-by: Shravya Kumbham <[email protected]>
> Signed-off-by: Radhey Shyam Pandey <[email protected]>
Any reason not to apply this to net as a fix?
> diff --git a/drivers/net/ethernet/xilinx/xilinx_emaclite.c b/drivers/net/ethernet/xilinx/xilinx_emaclite.c
> index 0c26f5b..fc5ccd1 100644
> --- a/drivers/net/ethernet/xilinx/xilinx_emaclite.c
> +++ b/drivers/net/ethernet/xilinx/xilinx_emaclite.c
> @@ -820,7 +820,7 @@ static int xemaclite_mdio_write(struct mii_bus *bus, int phy_id, int reg,
> static int xemaclite_mdio_setup(struct net_local *lp, struct device *dev)
> {
> struct mii_bus *bus;
> - int rc;
> + int rc, ret;
> struct resource res;
> struct device_node *np = of_get_parent(lp->phy_node);
> struct device_node *npp;
> @@ -834,7 +834,13 @@ static int xemaclite_mdio_setup(struct net_local *lp, struct device *dev)
> }
> npp = of_get_parent(np);
>
> - of_address_to_resource(npp, 0, &res);
> + ret = of_address_to_resource(npp, 0, &res);
> + if (ret) {
> + dev_err(dev, "%s resource error!\n",
> + dev->of_node->full_name);
> + of_node_put(lp->phy_node);
I'm always confused by the of_* refcounting. Why do you need to put
phy_node here, and nowhere else in this function?
> + return ret;
> + }
> /* Restart auto negotiation */
> bmcr = phy_read(lp->phy_dev, MII_BMCR);
> + if (bmcr < 0) {
> + dev_err(&lp->ndev->dev, "phy_read failed\n");
> + phy_disconnect(lp->phy_dev);
> + lp->phy_dev = NULL;
> +
> + return bmcr;
> + }
> bmcr |= (BMCR_ANENABLE | BMCR_ANRESTART);
> phy_write(lp->phy_dev, MII_BMCR, bmcr);
Does it really make much sense to validate the return value of
phy_read() but not check any errors from phy_write()s?
> -----Original Message-----
> From: Jakub Kicinski <[email protected]>
> Sent: Sunday, November 8, 2020 1:05 AM
> To: Radhey Shyam Pandey <[email protected]>
> Cc: [email protected]; Michal Simek <[email protected]>;
> [email protected]; [email protected]; linux-
> [email protected]; git <[email protected]>; Shravya Kumbham
> <[email protected]>
> Subject: Re: [PATCH net-next] net: emaclite: Add error handling for
> of_address_ and phy read functions
>
> On Tue, 3 Nov 2020 19:01:05 +0530 Radhey Shyam Pandey wrote:
> > From: Shravya Kumbham <[email protected]>
> >
> > Add ret variable, conditions to check the return value and it's error
> > path for of_address_to_resource() and phy_read() functions.
> >
> > Addresses-Coverity: Event check_return value.
> > Signed-off-by: Shravya Kumbham <[email protected]>
> > Signed-off-by: Radhey Shyam Pandey <[email protected]>
>
> Any reason not to apply this to net as a fix?
Yes, it can be applied to net as a fix.
>
> > diff --git a/drivers/net/ethernet/xilinx/xilinx_emaclite.c
> > b/drivers/net/ethernet/xilinx/xilinx_emaclite.c
> > index 0c26f5b..fc5ccd1 100644
> > --- a/drivers/net/ethernet/xilinx/xilinx_emaclite.c
> > +++ b/drivers/net/ethernet/xilinx/xilinx_emaclite.c
> > @@ -820,7 +820,7 @@ static int xemaclite_mdio_write(struct mii_bus
> > *bus, int phy_id, int reg, static int xemaclite_mdio_setup(struct
> > net_local *lp, struct device *dev) {
> > struct mii_bus *bus;
> > - int rc;
> > + int rc, ret;
> > struct resource res;
> > struct device_node *np = of_get_parent(lp->phy_node);
> > struct device_node *npp;
> > @@ -834,7 +834,13 @@ static int xemaclite_mdio_setup(struct net_local
> *lp, struct device *dev)
> > }
> > npp = of_get_parent(np);
> >
> > - of_address_to_resource(npp, 0, &res);
> > + ret = of_address_to_resource(npp, 0, &res);
> > + if (ret) {
> > + dev_err(dev, "%s resource error!\n",
> > + dev->of_node->full_name);
> > + of_node_put(lp->phy_node);
>
> I'm always confused by the of_* refcounting. Why do you need to put
> phy_node here, and nowhere else in this function?
Initially, we added of_node_put(phy_node) thinking about this
particular coverity change. But agree it has to be added for
all error path i.e better place would be in xemaclite_of_probe()
error label.
>
> > + return ret;
> > + }
>
> > /* Restart auto negotiation */
> > bmcr = phy_read(lp->phy_dev, MII_BMCR);
> > + if (bmcr < 0) {
> > + dev_err(&lp->ndev->dev, "phy_read failed\n");
> > + phy_disconnect(lp->phy_dev);
> > + lp->phy_dev = NULL;
> > +
> > + return bmcr;
> > + }
> > bmcr |= (BMCR_ANENABLE | BMCR_ANRESTART);
> > phy_write(lp->phy_dev, MII_BMCR, bmcr);
>
> Does it really make much sense to validate the return value of
> phy_read() but not check any errors from phy_write()s?
Error handling was added for phy_read as it was using return value
and reported by coverity. But yes we in a follow-up patch we
can extend error handling for phy_write as well.