On 2015. 8. 1., at AM 12:09, Gabriele Paoloni <gabriele.paoloni@xxxxxxxxxx> wrote: > >> -----Original Message----- >> From: Kishon Vijay Abraham I [mailto:kishon@xxxxxx] >> Sent: Friday, July 31, 2015 3:57 PM >> To: Gabriele Paoloni; Rob Herring >> Cc: Bjorn Helgaas; arnd@xxxxxxxx; lorenzo.pieralisi@xxxxxxx; Wangzhou >> (B); robh+dt@xxxxxxxxxx; james.morse@xxxxxxx; Liviu.Dudau@xxxxxxx; >> linux-pci@xxxxxxxxxxxxxxx; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; >> devicetree@xxxxxxxxxxxxxxx; Yuanzhichang; Zhudacai; zhangjukuo; >> qiuzhenfa; Liguozhu (Kenneth); Jingoo Han; Pratyush Anand; Arnd >> Bergmann; Arnd Bergmann >> Subject: Re: [PATCH v6] PCI: Store PCIe bus address in struct >> of_pci_range >> >> +Arnd >> >> Hi, >> >>> On Friday 31 July 2015 07:55 PM, Gabriele Paoloni wrote: >>> [+cc Kishon] >>> >>>> -----Original Message----- >>>> From: linux-pci-owner@xxxxxxxxxxxxxxx [mailto:linux-pci- >>>> owner@xxxxxxxxxxxxxxx] On Behalf Of Rob Herring >>>> Sent: Thursday, July 30, 2015 9:42 PM >>>> To: Gabriele Paoloni >>>> Cc: Bjorn Helgaas; arnd@xxxxxxxx; lorenzo.pieralisi@xxxxxxx; >> Wangzhou >>>> (B); robh+dt@xxxxxxxxxx; james.morse@xxxxxxx; Liviu.Dudau@xxxxxxx; >>>> linux-pci@xxxxxxxxxxxxxxx; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; >>>> devicetree@xxxxxxxxxxxxxxx; Yuanzhichang; Zhudacai; zhangjukuo; >>>> qiuzhenfa; Liguozhu (Kenneth); Jingoo Han; Pratyush Anand >>>> Subject: Re: [PATCH v6] PCI: Store PCIe bus address in struct >>>> of_pci_range >>>> >>>> On Thu, Jul 30, 2015 at 12:34 PM, Gabriele Paoloni >>>> <gabriele.paoloni@xxxxxxxxxx> wrote: >>>>>> -----Original Message----- >>>>>> From: Bjorn Helgaas [mailto:bhelgaas@xxxxxxxxxx] >>>>>> Sent: 30 July 2015 18:15 >>>>>> On Thu, Jul 30, 2015 at 04:50:55PM +0000, Gabriele Paoloni wrote: >>>>>>>> -----Original Message----- >>>>>>>> From: linux-pci-owner@xxxxxxxxxxxxxxx [mailto:linux-pci- >>>>>>>> owner@xxxxxxxxxxxxxxx] On Behalf Of Bjorn Helgaas >>>>>>>> Sent: Thursday, July 30, 2015 5:15 PM >>>>>>>> On Thu, Jul 30, 2015 at 01:52:13PM +0000, Gabriele Paoloni wrote: >>>> >>>> [...] >>>> >>>>>>>>> I don’t think we should rely on [CPU] addresses...what if the >>>>>>>> intermediate >>>>>>>>> translation layer changes the lower significant bits of the >>>> "bus >>>>>>>> address" >>>>>>>>> to translate into a cpu address? >>>>>>>> >>>>>>>> Is it really a possiblity that the lower bits could be changed? >>>>>>> >>>>>>> I've checked all the current deignware users DTs except "pci- >>>>>> layerscape" >>>>>>> that I could not find: >>>>>>> spear1310.dtsi >>>>>>> spear1340.dtsi >>>>>>> dra7.dtsi >>>>>>> imx6qdl.dtsi >>>>>>> imx6sx.dtsi >>>>>>> keystone.dtsi >>>>>>> exynos5440.dtsi >>>>>>> >>>>>>> None of them modifies the lower bits. To be more precise the only >>>> guy >>>>>>> that provides another translation layer is "dra7.dtsi": >>>>>>> axi0 >>>>>>> http://lxr.free- >>>> electrons.com/source/arch/arm/boot/dts/dra7.dtsi#L207 >>>>>>> >>>>>>> axi1 >>>>>>> http://lxr.free- >>>> electrons.com/source/arch/arm/boot/dts/dra7.dtsi#L241 >>>>>>> >>>>>>> For this case masking the top 4bits (bits28 to 31) should make >> the >>>> job. >>>> >>>> IMO, we should just fix this case. After further study, I don't >> think >>>> this is a DW issue, but rather an SOC integration issue. >>>> >>>> I believe you can just fixup the address in the pp->ops->host_init >> hook. Yep, it is SOC specific code for dra7. This is NOT a DW issue. >>> >>> Yes I guess that I could just assign pp->(*)_mod_base to the CPU >> address >>> in DW and mask it out in dra7xx_pcie_host_init()... >>> >>> Kishon, would you be ok with that? >> >> Initially I was using *base-mask* property from dt. Me and Arnd (cc'ed) >> had >> this discussion [1] before we decided the current approach. It'll be >> good to >> check with Arnd too. >> >> [1] -> http://lists.infradead.org/pipermail/linux-arm-kernel/2014- >> May/253528.html > > > In this patch you use the mask into designware....instead the approach > proposed by Rob means to have the mask declared in the dra7 driver and > you modified the pp members in dra7xx_pcie_host_init by masking them... I want to move that code to dra7 driver, because that code is dra7-specific. Best regards, Jingoo Han > BTW good to have Arnd opinion too.. >> >> Thanks >> Kishon -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
