Hi Marek: > -----Original Message----- > From: Marek Vasut [mailto:marex@xxxxxxx] > Sent: Wednesday, December 04, 2013 3:52 PM > To: Zhu Richard-R65037 > Cc: Jingoo Han; 'Tim Harvey'; 'Pratyush Anand'; linux-arm- > kernel@xxxxxxxxxxxxxxxxxxx; linux-pci@xxxxxxxxxxxxxxx; 'Bjorn Helgaas'; 'Frank > Li'; 'Harro Haan'; 'Mohit KUMAR DCG'; 'Sascha Hauer'; 'Sean Cross'; 'Shawn > Guo'; 'Siva Reddy Kallam'; 'Srikanth T Shivanand'; 'Troy Kisky'; 'Yinghai Lu' > Subject: Re: [PATCH 2/7] [RFC] PCI: imx6: remove outbound io/mem ATU region > mapping > > On Wednesday, December 04, 2013 at 06:49:55 AM, Richard Zhu wrote: > > Hi Marek: > > > > Best Regards > > Richard Zhu > > > > > -----Original Message----- > > > From: Marek Vasut [mailto:marex@xxxxxxx] > > > Sent: Friday, November 29, 2013 1:56 AM > > > To: Jingoo Han > > > Cc: 'Tim Harvey'; 'Pratyush Anand'; > > > linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; > > > linux-pci@xxxxxxxxxxxxxxx; 'Bjorn Helgaas'; 'Frank Li'; 'Harro > > > Haan'; 'Mohit KUMAR DCG'; Zhu Richard-R65037; 'Sascha Hauer'; 'Sean > > > Cross'; 'Shawn Guo'; 'Siva Reddy Kallam'; 'Srikanth T Shivanand'; > > > 'Troy Kisky'; 'Yinghai Lu' Subject: Re: [PATCH 2/7] [RFC] PCI: imx6: > > > remove outbound io/mem ATU region mapping > > > > > > Dear Jingoo Han, > > > > > > > On Wednesday, November 27, 2013 5:44 PM, Marek Vasut wrote: > > > > > Wednesday, November 27, 2013 1:30 PM, Pratyush Anand wrote: > > > > > > On Wed, Nov 27, 2013 at 05:10:43AM +0800, Marek Vasut wrote: > > > > > > > From: Tim Harvey <tharvey@xxxxxxxxxxxxx> > > > > > > > > > > > > > > The IMX6 iATU is used for address translation between the > > > > > > > AXI bus address space and PCI address space. This is used > > > > > > > for type0 and > > > > > > > type1 config cycles but is not necessary for outbound io/mem > > > > > > > regions. > > > > > > > > > > > > > > This patch removes the calls that inappropriately > > > > > > > re-configures the ATU viewport for outbound memory and IO > > > > > > > after config cycles and removes them altogether as they are not > necessary. > > > > > > > > > > > > Yes, they are not necessary for all the cases where > > > > > > translation is one to one. So so for sure all the platform > > > > > > till now introduced should work. > > > > > > But, what about a platform where memory translation is not one > > > > > > to one? > > > > > > > > > > > > Existing code should work with all sort of memory translation > > > > > > on a platform having atleast two viewports capable of > > > > > > programming any type of outbound transaction. > > > > > > > > > > Full ACK, that's why it's called RFC. > > > > > > > > > > > > This resolves issues with PCI devices behind switches and > > > > > > > has been tested with a Gige device behind a PLX PEX860x switch. > > > > > > > More testing is needed for other configurations. > > > > > > > > > > > > I do not understand if MX6 has 4 Outbound Viewport then how > > > > > > this patch helps? > > > > > > -- PCI devices behind switches would not have been working > > > > > > because > > > > > > CFG1 transaction would not have been correct. > > > > > > -- It works with this patch. This patch changes viewport for > > > > > > CFG1 from > > > > > > 1 to 0. > > > > > > -- Can it be possible that MX6 has some restriction on > > > > > > viewport programming capability. I mean,like only viewport0 > > > > > > can be programmed for CFG0/1? > > > > > > > > > > Tim ? > > > > > > > > > > Here is the MX6 datasheet [1], the section 48.3.9.1.1 and > > > > > 48.3.9.1.2 describe the iATU configuration on MX6. My > > > > > understanding from this description is that the MX6 has 4 > > > > > inbound and 4 outbound iATU regions. Am I wrong ? > > > > > > > > The numbers of inbound and outbound are hardware-configurable features. > > > > Thus, these numbers can be confirmed by Freescale hardware engineers. > > > > How about asking Freescale hardware engineers, if possible? > > > > > > Richard is on the CC. Richard, can you please confirm those? > > > > [Richard] One Pericom PI7C9X2G303EL pcie switch, and two pcie ep > > deivces(one is intel e1000e nic, the other is one xhci device) are > > tested on imx6q sabresd board. Without removing outbound io/mem > > regions view map during the cfg0/1 read/write cycle, both of these > > devices can't work well at my side. Works well after remove them > > during the cfg0/1 read/write cycles. > > Same to Tim's situation about switch implementation. > > Thanks Richard! I am just wondering what kind of conclusion can we draw from > this. Let me reiterate what we have: > > - i.MX6 has 4 inbound and 4 outbound iATU regions, is that correct, Richard? > - If we program the iATU regions, the i.MX6 PCIe doesn't work with switch. > > Is there some special sause to the iATU on MX6 maybe ? [Richard] welcome, it's correct, imx6 pcie has 4 inbount and 4 outbound iATU regions. Imx6 pcie doesn't work with switch if the following view switches are not removed in The cfg0/1 read/write cycles. @@ -516,9 +560,11 @@ static int dw_pcie_rd_other_conf(struct pcie_port *pp, struct pci_bus *bus, if (bus->parent->number == pp->root_bus_nr) { dw_pcie_prog_viewport_cfg0(pp, busdev); ret = cfg_read(pp->va_cfg0_base + address, where, size, val); + // dw_pcie_prog_viewport_mem_outbound(pp); } else { dw_pcie_prog_viewport_cfg1(pp, busdev); ret = cfg_read(pp->va_cfg1_base + address, where, size, val); + // dw_pcie_prog_viewport_io_outbound(pp); } return ret; @@ -537,9 +583,11 @@ static int dw_pcie_wr_other_conf(struct pcie_port *pp, struct pci_bus *bus, if (bus->parent->number == pp->root_bus_nr) { dw_pcie_prog_viewport_cfg0(pp, busdev); ret = cfg_write(pp->va_cfg0_base + address, where, size, val); + // dw_pcie_prog_viewport_mem_outbound(pp); } else { dw_pcie_prog_viewport_cfg1(pp, busdev); ret = cfg_write(pp->va_cfg1_base + address, where, size, val); + // dw_pcie_prog_viewport_io_outbound(pp); } return ret; Best Regards Richard Zhu -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
