Re: [PATCH 2/8] net: pxa168_eth: Use platform_get_irq() to get the interrupt

From: "Lad, Prabhakar" <prabhakar.csengg@gmail.com>
To: Heiner Kallweit <hkallweit1@gmail.com>
Cc: Andy Shevchenko <andy.shevchenko@gmail.com>,
	Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>,
	"netdev@vger.kernel.org" <netdev@vger.kernel.org>,
	"David S. Miller" <davem@davemloft.net>,
	Jakub Kicinski <kuba@kernel.org>,
	Rob Herring <robh+dt@kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 2/8] net: pxa168_eth: Use platform_get_irq() to get the interrupt
Date: Sun, 26 Dec 2021 14:24:36 +0000	[thread overview]
Message-ID: <CA+V-a8uykb1=LVgi7NPsBxkGwh2Dwzy0JggbLnsWk05oHQ4NOQ@mail.gmail.com> (raw)
In-Reply-To: <bb5a43e5-6036-3788-71ca-c411611e0ad9@gmail.com>

Hi Heiner,

Thank you for the review.

On Sun, Dec 26, 2021 at 11:15 AM Heiner Kallweit <hkallweit1@gmail.com> wrote:
>
> On 25.12.2021 13:19, Lad, Prabhakar wrote:
> > Hi Andy,
> >
> > Thank you for the review.
> >
> > On Sat, Dec 25, 2021 at 11:24 AM Andy Shevchenko
> > <andy.shevchenko@gmail.com> wrote:
> >>
> >>
> >>
> >> On Friday, December 24, 2021, Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> wrote:
> >>>
> >>> platform_get_resource(pdev, IORESOURCE_IRQ, ..) relies on static
> >>> allocation of IRQ resources in DT core code, this causes an issue
> >>> when using hierarchical interrupt domains using "interrupts" property
> >>> in the node as this bypasses the hierarchical setup and messes up the
> >>> irq chaining.
> >>>
> >>> In preparation for removal of static setup of IRQ resource from DT core
> >>> code use platform_get_irq().
> >>>
> >>> Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> >>> ---
> >>>  drivers/net/ethernet/marvell/pxa168_eth.c | 9 +++++----
> >>>  1 file changed, 5 insertions(+), 4 deletions(-)
> >>>
> >>> diff --git a/drivers/net/ethernet/marvell/pxa168_eth.c b/drivers/net/ethernet/marvell/pxa168_eth.c
> >>> index 1d607bc6b59e..52bef50f5a0d 100644
> >>> --- a/drivers/net/ethernet/marvell/pxa168_eth.c
> >>> +++ b/drivers/net/ethernet/marvell/pxa168_eth.c
> >>> @@ -1388,7 +1388,6 @@ static int pxa168_eth_probe(struct platform_device *pdev)
> >>>  {
> >>>         struct pxa168_eth_private *pep = NULL;
> >>>         struct net_device *dev = NULL;
> >>> -       struct resource *res;
> >>>         struct clk *clk;
> >>>         struct device_node *np;
> >>>         int err;
> >>> @@ -1419,9 +1418,11 @@ static int pxa168_eth_probe(struct platform_device *pdev)
> >>>                 goto err_netdev;
> >>>         }
> >>>
> >>> -       res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
> >>> -       BUG_ON(!res);
> >>> -       dev->irq = res->start;
> >>> +       err = platform_get_irq(pdev, 0);
> >>> +       if (err == -EPROBE_DEFER)
> >>
> >>
> >>  What about other errors?
> >>
> > Ouch I missed it...
> >>
> >>>
> >>> +               goto err_netdev;
> >>> +       BUG_ON(dev->irq < 0);
> >>
> >>
> >> ??? What is this and how it supposed to work?
> >>
> >
> .. should have been BUG_ON(dev->irq < 0);
>
> Usage of BUG_ON() is discouraged. Better handle the error w/o stopping
> the whole system.
>
Agreed, if everyone is OK i'll create a separate patch for removal of
BUG_ON() and the later patch for using platform_get_irq().

Cheers,
Prabhakar