Re: [PATCH] imx: Provide correct number of resources when registering gpio devices

From: Guenter Roeck <linux@roeck-us.net>
To: Bjorn Helgaas <helgaas@kernel.org>
Cc: Shawn Guo <shawnguo@kernel.org>,
	Sascha Hauer <s.hauer@pengutronix.de>,
	Russell King <linux@armlinux.org.uk>,
	linux-kernel@vger.kernel.org, NXP Linux Team <linux-imx@nxp.com>,
	Pengutronix Kernel Team <kernel@pengutronix.de>,
	Bjorn Helgaas <bhelgaas@google.com>,
	Fabio Estevam <festevam@gmail.com>,
	linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH] imx: Provide correct number of resources when registering gpio devices
Date: Wed, 1 Jul 2020 09:16:53 -0700	[thread overview]
Message-ID: <20200701161653.GA72983@roeck-us.net> (raw)
In-Reply-To: <20200701152442.GA3609842@bjorn-Precision-5520>

On Wed, Jul 01, 2020 at 10:24:42AM -0500, Bjorn Helgaas wrote:
> On Tue, Jun 30, 2020 at 08:26:51PM -0700, Guenter Roeck wrote:
> > Since commit a85a6c86c25be ("driver core: platform: Clarify that IRQ 0 is
> > invalid"), the kernel is a bit touchy when it encounters interrupt 0.
> > As a result, there are lots of warnings such as the following when booting
> > systems such as 'kzm'.
> 
> Thanks for the fix.  If there are others like this, I'd be glad to
> help fix them since I made the kernel grumpier about this.  Just point
> me at the info.
> 
> I looked at other callers of platform_device_register_resndata().  It
> looks like imx_add_imx_dma() and vm_cmdline_set() have the same
> problem.  I'll fix those unless you're already doing it.

The traceback below is the only one I have seen in my test system.
Qemu doesn't support any of the architectures calling imx_add_imx_dma.

I have not looked at or searched for any others.

Guenter

> 
> > WARNING: CPU: 0 PID: 1 at drivers/base/platform.c:224 platform_get_irq_optional+0x118/0x128
> > 0 is an invalid IRQ number
> > Modules linked in:
> > CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.8.0-rc3 #1
> > Hardware name: Kyoto Microcomputer Co., Ltd. KZM-ARM11-01
> > [<c01127d4>] (unwind_backtrace) from [<c010c620>] (show_stack+0x10/0x14)
> > [<c010c620>] (show_stack) from [<c06f5f54>] (dump_stack+0xe8/0x120)
> > [<c06f5f54>] (dump_stack) from [<c0128878>] (__warn+0xe4/0x108)
> > [<c0128878>] (__warn) from [<c0128910>] (warn_slowpath_fmt+0x74/0xbc)
> > [<c0128910>] (warn_slowpath_fmt) from [<c08b8e84>] (platform_get_irq_optional+0x118/0x128)
> > [<c08b8e84>] (platform_get_irq_optional) from [<c08b8eb4>] (platform_irq_count+0x20/0x3c)
> > [<c08b8eb4>] (platform_irq_count) from [<c0728660>] (mxc_gpio_probe+0x8c/0x494)
> > [<c0728660>] (mxc_gpio_probe) from [<c08b93cc>] (platform_drv_probe+0x48/0x98)
> > [<c08b93cc>] (platform_drv_probe) from [<c08b703c>] (really_probe+0x214/0x344)
> > [<c08b703c>] (really_probe) from [<c08b7274>] (driver_probe_device+0x58/0xb4)
> > [<c08b7274>] (driver_probe_device) from [<c08b7478>] (device_driver_attach+0x58/0x60)
> > [<c08b7478>] (device_driver_attach) from [<c08b7504>] (__driver_attach+0x84/0xc0)
> > [<c08b7504>] (__driver_attach) from [<c08b50f8>] (bus_for_each_dev+0x78/0xb8)
> > [<c08b50f8>] (bus_for_each_dev) from [<c08b62cc>] (bus_add_driver+0x154/0x1e0)
> > [<c08b62cc>] (bus_add_driver) from [<c08b82b8>] (driver_register+0x74/0x108)
> > [<c08b82b8>] (driver_register) from [<c0102320>] (do_one_initcall+0x80/0x3b4)
> > [<c0102320>] (do_one_initcall) from [<c1501008>] (kernel_init_freeable+0x170/0x208)
> > [<c1501008>] (kernel_init_freeable) from [<c0e178d4>] (kernel_init+0x8/0x11c)
> > [<c0e178d4>] (kernel_init) from [<c0100134>] (ret_from_fork+0x14/0x20)
> > 
> > As it turns out, mxc_register_gpio() is a bit lax when setting the
> > number of resources: it registers a resource with interrupt 0 when in
> > reality there is no such interrupt. Fix the problem by not declaring
> > the second interrupt resource if there is no second interrupt.
> > 
> > Fixes: a85a6c86c25be ("driver core: platform: Clarify that IRQ 0 is invalid")
> > Cc: Bjorn Helgaas <bhelgaas@google.com>
> > Signed-off-by: Guenter Roeck <linux@roeck-us.net>
> > ---
> >  arch/arm/mach-imx/devices/platform-gpio-mxc.c | 5 +++--
> >  1 file changed, 3 insertions(+), 2 deletions(-)
> > 
> > diff --git a/arch/arm/mach-imx/devices/platform-gpio-mxc.c b/arch/arm/mach-imx/devices/platform-gpio-mxc.c
> > index 78628ef12672..355de845224c 100644
> > --- a/arch/arm/mach-imx/devices/platform-gpio-mxc.c
> > +++ b/arch/arm/mach-imx/devices/platform-gpio-mxc.c
> > @@ -24,7 +24,8 @@ struct platform_device *__init mxc_register_gpio(char *name, int id,
> >  			.flags = IORESOURCE_IRQ,
> >  		},
> >  	};
> > +	unsigned int nres;
> >  
> > -	return platform_device_register_resndata(&mxc_aips_bus,
> > -			name, id, res, ARRAY_SIZE(res), NULL, 0);
> > +	nres = irq_high ? ARRAY_SIZE(res) : ARRAY_SIZE(res) - 1;
> > +	return platform_device_register_resndata(&mxc_aips_bus, name, id, res, nres, NULL, 0);
> >  }
> > -- 
> > 2.17.1
> > 

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