From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Return-Path: Message-ID: <1497923734.42572.8.camel@intel.com> Subject: Re: [PATCH v5 1/4] PCI: xilinx: Create legacy IRQ domain with size 5 From: Ley Foon Tan To: Bjorn Helgaas Cc: Paul Burton , linux-pci@vger.kernel.org, Bharat Kumar Gogada , Ravikiran Gummaluri , Bjorn Helgaas , Michal Simek , linux-mips@linux-mips.org, Thomas Gleixner , Ley Foon Tan , Marc Zyngier Date: Tue, 20 Jun 2017 09:55:34 +0800 In-Reply-To: <20170620014903.GI554@bhelgaas-glaptop.roam.corp.google.com> References: <20170617195741.12757-1-paul.burton@imgtec.com> <20170617195741.12757-2-paul.burton@imgtec.com> <20170619234708.GG554@bhelgaas-glaptop.roam.corp.google.com> <1497919094.42572.3.camel@intel.com> <20170620014903.GI554@bhelgaas-glaptop.roam.corp.google.com> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 List-ID: On Mon, 2017-06-19 at 20:49 -0500, Bjorn Helgaas wrote: > [+cc Marc] >=20 > On Tue, Jun 20, 2017 at 08:38:14AM +0800, Ley Foon Tan wrote: > >=20 > > On Mon, 2017-06-19 at 18:47 -0500, Bjorn Helgaas wrote: > > >=20 > > > [+cc Thomas, Ley Foon] > > >=20 > > > On Sat, Jun 17, 2017 at 12:57:38PM -0700, Paul Burton wrote: > > > >=20 > > > >=20 > > > > The driver expects to use hardware IRQ numbers 1 through 4 for > > > > INTX > > > > interrupts, but only creates an IRQ domain of size 4 (ie. IRQ > > > > numbers 0 > > > > through 3). This results in a warning from irq_domain_associate > > > > when it > > > > is called with hwirq=3D4: > > > >=20 > > > > =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0WARNING: CPU: 0 PID: 1 at kernel/irq/= irqdomain.c:365 > > > > =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0irq_domain_as= sociate+0x170/0x220 > > > > =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0error: hwirq 0x4 is too large for dum= my > > > > =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0Modules linked in: > > > > =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0CPU: 0 PID: 1 Comm: swapper/0 Tainted= : G=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0W > > > > =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A04.12.0-rc5-00= 126-g19e1b3a10aad-dirty #427 > > > > =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0Stack : 0000000000000000 000000000000= 0004 0000000000000006 > > > > ffffffff8092c78a > > > > =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0= =C2=A0=C2=A00000000000000061 ffffffff8018bf60 0000000000000000 > > > > 0000000000000000 > > > > =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0= =C2=A0=C2=A0ffffffff8088c287 ffffffff80811d18 a8000000ffc60000 > > > > ffffffff80926678 > > > > =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0= =C2=A0=C2=A00000000000000001 0000000000000000 ffffffff80887880 > > > > ffffffff80960000 > > > > =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0= =C2=A0=C2=A0ffffffff80920000 ffffffff801e6744 ffffffff80887880 > > > > a8000000ffc4f8f8 > > > > =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0= =C2=A0=C2=A0000000000000089c ffffffff8018d260 0000000000010000 > > > > ffffffff80811d18 > > > > =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0= =C2=A0=C2=A00000000000000000 0000000000000001 0000000000000000 > > > > 0000000000000000 > > > > =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0= =C2=A0=C2=A00000000000000000 a8000000ffc4f840 0000000000000000 > > > > ffffffff8042cf34 > > > > =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0= =C2=A0=C2=A00000000000000000 0000000000000000 0000000000000000 > > > > 0000000000040c00 > > > > =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0= =C2=A0=C2=A00000000000000000 ffffffff8010d1c8 0000000000000000 > > > > ffffffff8042cf34 > > > > =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0= =C2=A0=C2=A0... > > > > =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0Call Trace: > > > > =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0[] show_stack+0x80/= 0xa0 > > > > =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0[] dump_stack+0xd4/= 0x110 > > > > =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0[] __warn+0xf0/0x10= 8 > > > > =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0[] warn_slowpath_fm= t+0x3c/0x48 > > > > =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0[] irq_domain_assoc= iate+0x170/0x220 > > > > =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0[] irq_create_mappi= ng+0x88/0x118 > > > > =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0[] irq_create_fwspe= c_mapping+0xb8/0x320 > > > > =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0[] irq_create_of_ma= pping+0x60/0x70 > > > > =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0[] of_irq_parse_and= _map_pci+0x20/0x38 > > > > =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0[] pci_fixup_irqs+0= x60/0xe0 > > > > =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0[] xilinx_pcie_prob= e+0x28c/0x478 > > > > =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0[] platform_drv_pro= be+0x50/0xd0 > > > > =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0[] driver_probe_dev= ice+0x2c4/0x3a0 > > > > =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0[] __driver_attach+= 0xc4/0xd0 > > > > =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0[] bus_for_each_dev= +0x64/0xa8 > > > > =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0[] bus_add_driver+0= x1f0/0x268 > > > > =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0[] driver_register+= 0x68/0x118 > > > > =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0[] do_one_initcall+= 0x4c/0x178 > > > > =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0[] kernel_init_free= able+0x204/0x2b0 > > > > =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0[] kernel_init+0x10= /0xf8 > > > > =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0[] ret_from_kernel_= thread+0x14/0x1c > > > >=20 > > > > This patch avoids that warning by creating the legacy IRQ > > > > domain > > > > with > > > > size 5 rather than 4, allowing it to cover the hwirq=3D4/INTD > > > > case. > > > >=20 > > > > Signed-off-by: Paul Burton > > > > Cc: Bharat Kumar Gogada > > > > Cc: Bjorn Helgaas > > > > Cc: Michal Simek > > > > Cc: Ravikiran Gummaluri > > > > Cc: linux-pci@vger.kernel.org > > > >=20 > > > > --- > > > >=20 > > > > Changes in v5: > > > > - New patch; replacing "PCI: xilinx: Fix INTX irq dispatch". > > > >=20 > > > > Changes in v4: None > > > > Changes in v3: None > > > > Changes in v2: None > > > >=20 > > > > =C2=A0drivers/pci/host/pcie-xilinx.c | 2 +- > > > > =C2=A01 file changed, 1 insertion(+), 1 deletion(-) > > > >=20 > > > > diff --git a/drivers/pci/host/pcie-xilinx.c > > > > b/drivers/pci/host/pcie-xilinx.c > > > > index 2fe2df51f9f8..94c71fb91648 100644 > > > > --- a/drivers/pci/host/pcie-xilinx.c > > > > +++ b/drivers/pci/host/pcie-xilinx.c > > > > @@ -524,7 +524,7 @@ static int > > > > xilinx_pcie_init_irq_domain(struct > > > > xilinx_pcie_port *port) > > > > =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0= =C2=A0=C2=A0=C2=A0return -ENODEV; > > > > =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0} > > > >=20 > > > > -=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0port->leg_domain =3D irq_domain_add_= linear(pcie_intc_node, > > > > 4, > > > > +=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0port->leg_domain =3D irq_domain_add_= linear(pcie_intc_node, > > > > 1 + > > > > 4, > > > I don't understand this.=C2=A0=C2=A0Several drivers call > > > irq_domain_add_linear() with > > > a size of 4: > > >=20 > > > =C2=A0 dra7xx_pcie_init_irq_domain > > > =C2=A0 ks_dw_pcie_host_init > > > =C2=A0 advk_pcie_init_irq_domain > > > =C2=A0 faraday_pci_setup_cascaded_irq > > > =C2=A0 rockchip_pcie_init_irq_domain > > > =C2=A0 nwl_pcie_init_irq_domain > > >=20 > > > Only one other in drivers/pci uses a size of 5: > > >=20 > > > =C2=A0 altera_pcie_init_irq_domain > > >=20 > > > Why can't we use a size of 4 for all of them?=C2=A0=C2=A0We only have= INTA- > > > INTD.=C2=A0=C2=A0Are > > > altera and xilinx missing something to apply an offset from the > > > 0-3 > > > space > > > to the 1-4 space? > > We have the same discussion before in 2016:=C2=A0https://lkml.org/lkml/= 2 > > 016/ > > 8/30/198 > Thanks for digging that out.=C2=A0=C2=A0I knew we'd discussed this before= , but > I > couldn't find it in the archives.=C2=A0=C2=A0I don't think anybody was re= ally > satisfied with the outcome, but we accepted it to make forward > progress. >=20 > >=20 > > This is because legacy interrupt is start with index 1 instead of > > 0. > I'm not buying this.=C2=A0=C2=A0Your argument was that "the hwirq for leg= acy > interrupts will start at 0x1 to 0x4 (INTA to INTD) and these values > are as per PCIe specification for legacy interrupts.=C2=A0=C2=A0So these = cannot > be numbered from 0." >=20 > But all the other drivers I mentioned get along with the 0-3 range > somehow.=C2=A0=C2=A0If there's something different about altera and xilin= x that > means they can't use the same solution the others do, I'd like to > know > what it is. I'm not sure those drivers with index 0-3 range tested with 4 legacy interrupts or not. It will not has error until someone requesting 4 legacy interrupts. We see this error when we enabling multi-function endpoint (4 functions). I believe this is not altera or xilinx specific. Regards Ley Foon