Re: [RFC 3/5] powerpc/mpic: Add support for non-contiguous irq ranges
On Wed, 2018-08-08 at 03:37 +, Bharat Bhushan wrote: > > -Original Message- > > From: Scott Wood [mailto:o...@buserror.net] > > Sent: Wednesday, August 8, 2018 2:34 AM > > To: Rob Herring ; Bharat Bhushan > > > > Cc: b...@kernel.crashing.org; pau...@samba.org; m...@ellerman.id.au; > > ga...@kernel.crashing.org; mark.rutl...@arm.com; > > kstew...@linuxfoundation.org; gre...@linuxfoundation.org; > > devicet...@vger.kernel.org; linuxppc-dev@lists.ozlabs.org; linux- > > ker...@vger.kernel.org; keesc...@chromium.org; > > tyr...@linux.vnet.ibm.com; j...@perches.com > > Subject: Re: [RFC 3/5] powerpc/mpic: Add support for non-contiguous irq > > ranges > > > > On Tue, 2018-08-07 at 12:09 -0600, Rob Herring wrote: > > > On Fri, Jul 27, 2018 at 03:17:59PM +0530, Bharat Bhushan wrote: > > > > Freescale MPIC h/w may not support all interrupt sources reported by > > > > hardware, "last-interrupt-source" or platform. On these platforms a > > > > misconfigured device tree that assigns one of the reserved > > > > interrupts leaves a non-functioning system without warning. > > > > > > There are lots of ways to misconfigure DTs. I don't think this is > > > special and needs a property. > > > > Yeah, the system will be just as non-functioning if you specify a valid- > > but- > > wrong-for-the-device interrupt number. > > Some is one additional benefits of this changes, MPIC have reserved regions > for un-supported interrupts and read/writes to these reserved regions seams > have no effect. > MPIC driver reads/writes to the reserved regions during init/uninit and > save/restore state. > > Let me know if it make sense to have these changes for mentioned reasons. The driver has been doing this forever with no ill effect. What is the motivation for this change? -Scott
RE: [RFC 3/5] powerpc/mpic: Add support for non-contiguous irq ranges
> -Original Message- > From: Scott Wood [mailto:o...@buserror.net] > Sent: Wednesday, August 8, 2018 11:21 AM > To: Bharat Bhushan ; Rob Herring > > Cc: b...@kernel.crashing.org; pau...@samba.org; m...@ellerman.id.au; > ga...@kernel.crashing.org; mark.rutl...@arm.com; > kstew...@linuxfoundation.org; gre...@linuxfoundation.org; > devicet...@vger.kernel.org; linuxppc-dev@lists.ozlabs.org; linux- > ker...@vger.kernel.org; keesc...@chromium.org; > tyr...@linux.vnet.ibm.com; j...@perches.com > Subject: Re: [RFC 3/5] powerpc/mpic: Add support for non-contiguous irq > ranges > > On Wed, 2018-08-08 at 03:37 +, Bharat Bhushan wrote: > > > -Original Message- > > > From: Scott Wood [mailto:o...@buserror.net] > > > Sent: Wednesday, August 8, 2018 2:34 AM > > > To: Rob Herring ; Bharat Bhushan > > > > > > Cc: b...@kernel.crashing.org; pau...@samba.org; m...@ellerman.id.au; > > > ga...@kernel.crashing.org; mark.rutl...@arm.com; > > > kstew...@linuxfoundation.org; gre...@linuxfoundation.org; > > > devicet...@vger.kernel.org; linuxppc-dev@lists.ozlabs.org; linux- > > > ker...@vger.kernel.org; keesc...@chromium.org; > > > tyr...@linux.vnet.ibm.com; j...@perches.com > > > Subject: Re: [RFC 3/5] powerpc/mpic: Add support for non-contiguous > > > irq ranges > > > > > > On Tue, 2018-08-07 at 12:09 -0600, Rob Herring wrote: > > > > On Fri, Jul 27, 2018 at 03:17:59PM +0530, Bharat Bhushan wrote: > > > > > Freescale MPIC h/w may not support all interrupt sources > > > > > reported by hardware, "last-interrupt-source" or platform. On > > > > > these platforms a misconfigured device tree that assigns one of > > > > > the reserved interrupts leaves a non-functioning system without > warning. > > > > > > > > There are lots of ways to misconfigure DTs. I don't think this is > > > > special and needs a property. > > > > > > Yeah, the system will be just as non-functioning if you specify a > > > valid- > > > but- > > > wrong-for-the-device interrupt number. > > > > Some is one additional benefits of this changes, MPIC have reserved > > regions for un-supported interrupts and read/writes to these reserved > > regions seams have no effect. > > MPIC driver reads/writes to the reserved regions during init/uninit > > and save/restore state. > > > > Let me know if it make sense to have these changes for mentioned > reasons. > > The driver has been doing this forever with no ill effect. Yes, there are no issue reported > What is the motivation for this change? On Simulation model I see warning when accessing the reserved region, So this patch is just an effort to improve. Thanks -Bharat > > -Scott
RE: [RFC 3/5] powerpc/mpic: Add support for non-contiguous irq ranges
> -Original Message- > From: Scott Wood [mailto:o...@buserror.net] > Sent: Wednesday, August 8, 2018 2:34 AM > To: Rob Herring ; Bharat Bhushan > > Cc: b...@kernel.crashing.org; pau...@samba.org; m...@ellerman.id.au; > ga...@kernel.crashing.org; mark.rutl...@arm.com; > kstew...@linuxfoundation.org; gre...@linuxfoundation.org; > devicet...@vger.kernel.org; linuxppc-dev@lists.ozlabs.org; linux- > ker...@vger.kernel.org; keesc...@chromium.org; > tyr...@linux.vnet.ibm.com; j...@perches.com > Subject: Re: [RFC 3/5] powerpc/mpic: Add support for non-contiguous irq > ranges > > On Tue, 2018-08-07 at 12:09 -0600, Rob Herring wrote: > > On Fri, Jul 27, 2018 at 03:17:59PM +0530, Bharat Bhushan wrote: > > > Freescale MPIC h/w may not support all interrupt sources reported by > > > hardware, "last-interrupt-source" or platform. On these platforms a > > > misconfigured device tree that assigns one of the reserved > > > interrupts leaves a non-functioning system without warning. > > > > There are lots of ways to misconfigure DTs. I don't think this is > > special and needs a property. > > Yeah, the system will be just as non-functioning if you specify a valid-but- > wrong-for-the-device interrupt number. Some is one additional benefits of this changes, MPIC have reserved regions for un-supported interrupts and read/writes to these reserved regions seams have no effect. MPIC driver reads/writes to the reserved regions during init/uninit and save/restore state. Let me know if it make sense to have these changes for mentioned reasons. Thanks -Bharat > > > We've had some interrupt mask or valid properties in the past, but > > generally don't accept those. > > FWIW, some of them like protected-sources and mpic-msgr-receive-mask > aren't for detecting errors, but are for partitioning (though the former is > obsolete with pic-no-reset). > > -Scott
Re: [RFC 3/5] powerpc/mpic: Add support for non-contiguous irq ranges
On Tue, 2018-08-07 at 12:09 -0600, Rob Herring wrote: > On Fri, Jul 27, 2018 at 03:17:59PM +0530, Bharat Bhushan wrote: > > Freescale MPIC h/w may not support all interrupt sources reported > > by hardware, "last-interrupt-source" or platform. On these platforms > > a misconfigured device tree that assigns one of the reserved > > interrupts leaves a non-functioning system without warning. > > There are lots of ways to misconfigure DTs. I don't think this is > special and needs a property. Yeah, the system will be just as non-functioning if you specify a valid-but- wrong-for-the-device interrupt number. > We've had some interrupt mask or valid > properties in the past, but generally don't accept those. FWIW, some of them like protected-sources and mpic-msgr-receive-mask aren't for detecting errors, but are for partitioning (though the former is obsolete with pic-no-reset). -Scott
Re: [RFC 3/5] powerpc/mpic: Add support for non-contiguous irq ranges
On Fri, Jul 27, 2018 at 03:17:59PM +0530, Bharat Bhushan wrote: > Freescale MPIC h/w may not support all interrupt sources reported > by hardware, "last-interrupt-source" or platform. On these platforms > a misconfigured device tree that assigns one of the reserved > interrupts leaves a non-functioning system without warning. There are lots of ways to misconfigure DTs. I don't think this is special and needs a property. We've had some interrupt mask or valid properties in the past, but generally don't accept those. > > This patch adds "supported-irq-ranges" property in device tree to > provide the range of supported source of interrupts. If a reserved > interrupt used then it will not be programming h/w, which it does > currently, and through warning. > > Signed-off-by: Bharat Bhushan > --- > .../devicetree/bindings/powerpc/fsl/mpic.txt | 8 ++ > arch/powerpc/include/asm/mpic.h| 9 ++ > arch/powerpc/sysdev/mpic.c | 113 > +++-- > 3 files changed, 121 insertions(+), 9 deletions(-)
