On Tue, Jan 13, 2015 at 12:54:40PM -0800, Tony Lindgren wrote:
> * Felipe Balbi <balbi@xxxxxx> [150113 11:55]:
> > On Tue, Jan 13, 2015 at 11:29:24AM -0800, Tony Lindgren wrote:
> > > --- a/drivers/net/ethernet/ti/davinci_emac.c
> > > +++ b/drivers/net/ethernet/ti/davinci_emac.c
> > > @@ -1538,7 +1538,7 @@ static int emac_dev_open(struct net_device *ndev)
> > > int i = 0;
> > > struct emac_priv *priv = netdev_priv(ndev);
> > >
> > > - pm_runtime_get(&priv->pdev->dev);
> > > + pm_runtime_get_sync(&priv->pdev->dev);
> >
> > gotta check return value on all pm_runtime_get_sync() calls. IIRC,
> > there's a coccinelle script for checking and patching this.
>
> Sure, here's an updated patch with error checking added.
>
> Regards,
>
> Tony
>
> 8< ---------------------
> From: Tony Lindgren <tony@xxxxxxxxxxx>
> Date: Mon, 22 Dec 2014 08:19:06 -0800
> Subject: [PATCH] net: davinci_emac: Fix runtime pm calls for davinci_emac
>
> Commit 3ba97381343b ("net: ethernet: davinci_emac: add pm_runtime support")
> added support for runtime PM, but it causes issues on omap3 related devices
> that actually gate the clocks:
>
> Unhandled fault: external abort on non-linefetch (0x1008)
> ...
> [<c04160f0>] (emac_dev_getnetstats) from [<c04d6a3c>] (dev_get_stats+0x78/0xc8)
> [<c04d6a3c>] (dev_get_stats) from [<c04e9ccc>] (rtnl_fill_ifinfo+0x3b8/0x938)
> [<c04e9ccc>] (rtnl_fill_ifinfo) from [<c04eade4>] (rtmsg_ifinfo+0x68/0xd8)
> [<c04eade4>] (rtmsg_ifinfo) from [<c04dd35c>] (register_netdevice+0x3a0/0x4ec)
> [<c04dd35c>] (register_netdevice) from [<c04dd4bc>] (register_netdev+0x14/0x24)
> [<c04dd4bc>] (register_netdev) from [<c041755c>] (davinci_emac_probe+0x408/0x5c8)
> [<c041755c>] (davinci_emac_probe) from [<c0396d78>] (platform_drv_probe+0x48/0xa4)
>
> Let's fix it by moving the pm_runtime_get() call earlier, and also add it to
> the emac_dev_getnetstats(). Also note that we want to use pm_runtime_get_sync()
> as we don't want to have deferred_resume happen. And let's also check the
> return value for pm_runtime_get_sync() as noted by Felipe Balbi <balbi@xxxxxx>.
>
> Cc: Brian Hutchinson <b.hutchman@xxxxxxxxx>
> Cc: Felipe Balbi <balbi@xxxxxx>
> Cc: Mark A. Greer <mgreer@xxxxxxxxxxxxxxx>
Reviewed-by: Felipe Balbi <balbi@xxxxxx>
> Signed-off-by: Tony Lindgren <tony@xxxxxxxxxxx>
>
> --- a/drivers/net/ethernet/ti/davinci_emac.c
> +++ b/drivers/net/ethernet/ti/davinci_emac.c
> @@ -1538,7 +1538,13 @@ static int emac_dev_open(struct net_device *ndev)
> int i = 0;
> struct emac_priv *priv = netdev_priv(ndev);
>
> - pm_runtime_get(&priv->pdev->dev);
> + ret = pm_runtime_get_sync(&priv->pdev->dev);
> + if (ret < 0) {
> + pm_runtime_put_noidle(&priv->pdev->dev);
> + dev_err(&priv->pdev->dev, "%s: failed to get_sync(%d)\n",
> + __func__, ret);
> + return ret;
> + }
>
> netif_carrier_off(ndev);
> for (cnt = 0; cnt < ETH_ALEN; cnt++)
> @@ -1725,6 +1731,15 @@ static struct net_device_stats *emac_dev_getnetstats(struct net_device *ndev)
> struct emac_priv *priv = netdev_priv(ndev);
> u32 mac_control;
> u32 stats_clear_mask;
> + int err;
> +
> + err = pm_runtime_get_sync(&priv->pdev->dev);
> + if (err < 0) {
> + pm_runtime_put_noidle(&priv->pdev->dev);
> + dev_err(&priv->pdev->dev, "%s: failed to get_sync(%d)\n",
> + __func__, err);
> + return &ndev->stats;
> + }
>
> /* update emac hardware stats and reset the registers*/
>
> @@ -1767,6 +1782,8 @@ static struct net_device_stats *emac_dev_getnetstats(struct net_device *ndev)
> ndev->stats.tx_fifo_errors += emac_read(EMAC_TXUNDERRUN);
> emac_write(EMAC_TXUNDERRUN, stats_clear_mask);
>
> + pm_runtime_put(&priv->pdev->dev);
> +
> return &ndev->stats;
> }
>
> @@ -1981,12 +1998,22 @@ static int davinci_emac_probe(struct platform_device *pdev)
> ndev->ethtool_ops = ðtool_ops;
> netif_napi_add(ndev, &priv->napi, emac_poll, EMAC_POLL_WEIGHT);
>
> + pm_runtime_enable(&pdev->dev);
> + rc = pm_runtime_get_sync(&pdev->dev);
> + if (rc < 0) {
> + pm_runtime_put_noidle(&pdev->dev);
> + dev_err(&pdev->dev, "%s: failed to get_sync(%d)\n",
> + __func__, rc);
> + goto no_cpdma_chan;
> + }
> +
> /* register the network device */
> SET_NETDEV_DEV(ndev, &pdev->dev);
> rc = register_netdev(ndev);
> if (rc) {
> dev_err(&pdev->dev, "error in register_netdev\n");
> rc = -ENODEV;
> + pm_runtime_put(&pdev->dev);
> goto no_cpdma_chan;
> }
>
> @@ -1996,9 +2023,7 @@ static int davinci_emac_probe(struct platform_device *pdev)
> "(regs: %p, irq: %d)\n",
> (void *)priv->emac_base_phys, ndev->irq);
> }
> -
> - pm_runtime_enable(&pdev->dev);
> - pm_runtime_resume(&pdev->dev);
> + pm_runtime_put(&pdev->dev);
>
> return 0;
>
--
balbi
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