Messages in this thread | | | From | Bharat Bhushan <> | Subject | RE: [RFC 5/5] powerpc/fsl: Add supported-irq-ranges for P2020 | Date | Wed, 8 Aug 2018 06:28:09 +0000 |
| |
> -----Original Message----- > From: Scott Wood [mailto:oss@buserror.net] > Sent: Wednesday, August 8, 2018 11:26 AM > To: Bharat Bhushan <bharat.bhushan@nxp.com>; > benh@kernel.crashing.org; paulus@samba.org; mpe@ellerman.id.au; > galak@kernel.crashing.org; mark.rutland@arm.com; > kstewart@linuxfoundation.org; gregkh@linuxfoundation.org; > devicetree@vger.kernel.org; linuxppc-dev@lists.ozlabs.org; linux- > kernel@vger.kernel.org > Cc: robh@kernel.org; keescook@chromium.org; tyreld@linux.vnet.ibm.com; > joe@perches.com > Subject: Re: [RFC 5/5] powerpc/fsl: Add supported-irq-ranges for P2020 > > On Wed, 2018-08-08 at 03:44 +0000, Bharat Bhushan wrote: > > > -----Original Message----- > > > From: Scott Wood [mailto:oss@buserror.net] > > > Sent: Wednesday, August 8, 2018 2:44 AM > > > To: Bharat Bhushan <bharat.bhushan@nxp.com>; > > > benh@kernel.crashing.org; paulus@samba.org; mpe@ellerman.id.au; > > > galak@kernel.crashing.org; mark.rutland@arm.com; > > > kstewart@linuxfoundation.org; gregkh@linuxfoundation.org; > > > devicetree@vger.kernel.org; linuxppc-dev@lists.ozlabs.org; linux- > > > kernel@vger.kernel.org > > > Cc: robh@kernel.org; keescook@chromium.org; > > > tyreld@linux.vnet.ibm.com; joe@perches.com > > > Subject: Re: [RFC 5/5] powerpc/fsl: Add supported-irq-ranges for > > > P2020 > > > > > > On Fri, 2018-07-27 at 15:18 +0530, Bharat Bhushan wrote: > > > > MPIC on NXP (Freescale) P2020 supports following irq > > > > ranges: > > > > > 0 - 11 (External interrupt) > > > > > 16 - 79 (Internal interrupt) > > > > > 176 - 183 (Messaging interrupt) > > > > > 224 - 231 (Shared message signaled interrupt) > > > > > > Why don't you convert to the 4-cell interrupt specifiers that make > > > dealing with these ranges less error-prone? > > > > Ok , will do if we agree to have this series as per comment on other patch. > > If you're concerned with errors, this would be a good things to do regardless. > Actually, it seems that p2020si-post.dtsi already uses 4-cell interrupts. > > What is motivating this patchset? Is there something wrong in the existing > dts files?
There is no error in device tree. Main motivation is to improve code for following reasons: - While code study it was found that if a reserved irq-number used then there are no check in driver. irq will be configured as correct and interrupt will never fire. - Warnings were observed on development platform (simulator) when read/write to reserved MPIC reason during init.
> > > > > > > > > > > diff --git a/arch/powerpc/platforms/85xx/mpc85xx_rdb.c > > > > b/arch/powerpc/platforms/85xx/mpc85xx_rdb.c > > > > index 1006950..49ff348 100644 > > > > --- a/arch/powerpc/platforms/85xx/mpc85xx_rdb.c > > > > +++ b/arch/powerpc/platforms/85xx/mpc85xx_rdb.c > > > > @@ -57,6 +57,11 @@ void __init mpc85xx_rdb_pic_init(void) > > > > MPIC_BIG_ENDIAN | > > > > MPIC_SINGLE_DEST_CPU, > > > > 0, 256, " OpenPIC "); > > > > + } else if (of_machine_is_compatible("fsl,P2020RDB-PC")) { > > > > + mpic = mpic_alloc(NULL, 0, > > > > + MPIC_BIG_ENDIAN | > > > > + MPIC_SINGLE_DEST_CPU, > > > > + 0, 0, " OpenPIC "); > > > > } else { > > > > mpic = mpic_alloc(NULL, 0, > > > > MPIC_BIG_ENDIAN | > > > > > > I don't think we want to grow a list of every single revision of > > > every board in these platform files. > > > > One other confusing observation I have is that "irq_count" from > > platform code is given precedence over "last-interrupt-source" in device- > tree. > > Should not device-tree should have precedence otherwise there is no > > point using " last-interrupt-source" if platform code passes > > "irq_count" in mpic_alloc(). > > Maybe, though I don't think it matters much given that last-interrupt-source > was only added to avoid having to pass irq_count in platform code.
Thanks for clarifying;
My understanding was that "last-interrupt-source" added to ensure that we can over-ride value passed from platform code. In that case we do not need to change code and can control from device tree.
Thanks -Bharat
> > -Scott
| |