Re: [PATCH 2/3] net: asix: Avoid looping when the device is disconnected

From: Grant Grundler
Date: Mon Jul 25 2016 - 17:37:24 EST

On Mon, Jul 25, 2016 at 10:40 AM, <robert.foss@xxxxxxxxxxxxx> wrote:
> From: Vincent Palatin <vpalatin@xxxxxxxxxxxx>
>
> Check the answers from the USB stack and avoid re-sending multiple times
> the request if the device has disappeared.
>
> Signed-off-by: Vincent Palatin <vpalatin@xxxxxxxxxxxx>

The original chromium.org code review:
https://chromium-review.googlesource.com/255931

resulted in some additional commit message meta-data that would be
nice to include in the kernel.org commit message:
Reviewed-by: Julius Werner <jwerner@xxxxxxxxxxxx>
Reviewed-by: Douglas Anderson <dianders@xxxxxxxxxxxx>
Tested-by: Douglas Anderson <dianders@xxxxxxxxxxxx>

And yes, patch LGTM too. :)

cheers,
grant

> ---
> drivers/net/usb/asix_common.c | 56 +++++++++++++++++++++++++++++++++---------
> drivers/net/usb/asix_devices.c | 2 ++
> 2 files changed, 46 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/net/usb/asix_common.c b/drivers/net/usb/asix_common.c
> index f0ccf76..0339560 100644
> --- a/drivers/net/usb/asix_common.c
> +++ b/drivers/net/usb/asix_common.c
> @@ -428,13 +428,21 @@ int asix_mdio_read(struct net_device *netdev, int phy_id, int loc)
> __le16 res;
> u8 smsr;
> int i = 0;
> + int ret;
>
> mutex_lock(&dev->phy_mutex);
> do {
> - asix_set_sw_mii(dev, 0);
> + ret = asix_set_sw_mii(dev, 0);
> + if (ret == -ENODEV)
> + break;
> usleep_range(1000, 1100);
> - asix_read_cmd(dev, AX_CMD_STATMNGSTS_REG, 0, 0, 1, &smsr, 0);
> - } while (!(smsr & AX_HOST_EN) && (i++ < 30));
> + ret = asix_read_cmd(dev, AX_CMD_STATMNGSTS_REG,
> + 0, 0, 1, &smsr, 0);
> + } while (!(smsr & AX_HOST_EN) && (i++ < 30) && (ret != -ENODEV));
> + if (ret == -ENODEV) {
> + mutex_unlock(&dev->phy_mutex);
> + return ret;
> + }
>
> asix_read_cmd(dev, AX_CMD_READ_MII_REG, phy_id,
> (__u16)loc, 2, &res, 0);
> @@ -453,16 +461,24 @@ void asix_mdio_write(struct net_device *netdev, int phy_id, int loc, int val)
> __le16 res = cpu_to_le16(val);
> u8 smsr;
> int i = 0;
> + int ret;
>
> netdev_dbg(dev->net, "asix_mdio_write() phy_id=0x%02x, loc=0x%02x, val=0x%04x\n",
> phy_id, loc, val);
>
> mutex_lock(&dev->phy_mutex);
> do {
> - asix_set_sw_mii(dev, 0);
> + ret = asix_set_sw_mii(dev, 0);
> + if (ret == -ENODEV)
> + break;
> usleep_range(1000, 1100);
> - asix_read_cmd(dev, AX_CMD_STATMNGSTS_REG, 0, 0, 1, &smsr, 0);
> - } while (!(smsr & AX_HOST_EN) && (i++ < 30));
> + ret = asix_read_cmd(dev, AX_CMD_STATMNGSTS_REG,
> + 0, 0, 1, &smsr, 0);
> + } while (!(smsr & AX_HOST_EN) && (i++ < 30) && (ret != -ENODEV));
> + if (ret == -ENODEV) {
> + mutex_unlock(&dev->phy_mutex);
> + return;
> + }
>
> asix_write_cmd(dev, AX_CMD_WRITE_MII_REG, phy_id,
> (__u16)loc, 2, &res, 0);
> @@ -476,13 +492,21 @@ int asix_mdio_read_nopm(struct net_device *netdev, int phy_id, int loc)
> __le16 res;
> u8 smsr;
> int i = 0;
> + int ret;
>
> mutex_lock(&dev->phy_mutex);
> do {
> - asix_set_sw_mii(dev, 1);
> + ret = asix_set_sw_mii(dev, 1);
> + if (ret == -ENODEV)
> + break;
> usleep_range(1000, 1100);
> - asix_read_cmd(dev, AX_CMD_STATMNGSTS_REG, 0, 0, 1, &smsr, 1);
> - } while (!(smsr & AX_HOST_EN) && (i++ < 30));
> + ret = asix_read_cmd(dev, AX_CMD_STATMNGSTS_REG,
> + 0, 0, 1, &smsr, 1);
> + } while (!(smsr & AX_HOST_EN) && (i++ < 30) && (ret != -ENODEV));
> + if (ret == -ENODEV) {
> + mutex_unlock(&dev->phy_mutex);
> + return ret;
> + }
>
> asix_read_cmd(dev, AX_CMD_READ_MII_REG, phy_id,
> (__u16)loc, 2, &res, 1);
> @@ -502,16 +526,24 @@ asix_mdio_write_nopm(struct net_device *netdev, int phy_id, int loc, int val)
> __le16 res = cpu_to_le16(val);
> u8 smsr;
> int i = 0;
> + int ret;
>
> netdev_dbg(dev->net, "asix_mdio_write() phy_id=0x%02x, loc=0x%02x, val=0x%04x\n",
> phy_id, loc, val);
>
> mutex_lock(&dev->phy_mutex);
> do {
> - asix_set_sw_mii(dev, 1);
> + ret = asix_set_sw_mii(dev, 1);
> + if (ret == -ENODEV)
> + break;
> usleep_range(1000, 1100);
> - asix_read_cmd(dev, AX_CMD_STATMNGSTS_REG, 0, 0, 1, &smsr, 1);
> - } while (!(smsr & AX_HOST_EN) && (i++ < 30));
> + ret = asix_read_cmd(dev, AX_CMD_STATMNGSTS_REG,
> + 0, 0, 1, &smsr, 1);
> + } while (!(smsr & AX_HOST_EN) && (i++ < 30) && (ret != -ENODEV));
> + if (ret == -ENODEV) {
> + mutex_unlock(&dev->phy_mutex);
> + return;
> + }
>
> asix_write_cmd(dev, AX_CMD_WRITE_MII_REG, phy_id,
> (__u16)loc, 2, &res, 1);
> diff --git a/drivers/net/usb/asix_devices.c b/drivers/net/usb/asix_devices.c
> index aaa4290..ebeb730 100644
> --- a/drivers/net/usb/asix_devices.c
> +++ b/drivers/net/usb/asix_devices.c
> @@ -79,6 +79,8 @@ static u32 asix_get_phyid(struct usbnet *dev)
> /* Poll for the rare case the FW or phy isn't ready yet. */
> for (i = 0; i < 100; i++) {
> phy_reg = asix_mdio_read(dev->net, dev->mii.phy_id, MII_PHYSID1);
> + if (phy_reg < 0)
> + return 0;
> if (phy_reg != 0 && phy_reg != 0xFFFF)
> break;
> mdelay(1);
> --
> 2.7.4
>