Hi Jisheng > -----Original Message----- > From: Jisheng Zhang [mailto:jszhang@xxxxxxxxxxx] > Sent: 07 April 2016 09:35 > To: Gabriele Paoloni > Cc: jingoohan1@xxxxxxxxx; pratyush.anand@xxxxxxxxx; > bhelgaas@xxxxxxxxxx; linux-pci@xxxxxxxxxxxxxxx; linux- > kernel@xxxxxxxxxxxxxxx; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx > Subject: Re: [PATCH v2] PCI: designware: move remaining rc setup code > to dw_pcie_setup_rc() > > Hi Gabriele, > > On Thu, 7 Apr 2016 08:20:28 +0000 Gabriele Paoloni wrote: > > > Hi Jisheng > > > > Thanks for your reply > > > > > -----Original Message----- > > > From: Jisheng Zhang [mailto:jszhang@xxxxxxxxxxx] > > > Sent: 07 April 2016 03:38 > > > To: Gabriele Paoloni; jingoohan1@xxxxxxxxx; > pratyush.anand@xxxxxxxxx; > > > bhelgaas@xxxxxxxxxx > > > Cc: linux-pci@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; linux- > arm- > > > kernel@xxxxxxxxxxxxxxxxxxx > > > Subject: Re: [PATCH v2] PCI: designware: move remaining rc setup > code > > > to dw_pcie_setup_rc() > > > > > > Hi Gabriele, > > > > > > On Wed, 6 Apr 2016 14:50:29 +0000 Gabriele Paoloni wrote: > > > > > > > Hi, sorry to be late on this > > > > > > > > > -----Original Message----- > > > > > From: linux-kernel-owner@xxxxxxxxxxxxxxx [mailto:linux-kernel- > > > > > owner@xxxxxxxxxxxxxxx] On Behalf Of Jisheng Zhang > > > > > Sent: 16 March 2016 11:41 > > > > > To: jingoohan1@xxxxxxxxx; pratyush.anand@xxxxxxxxx; > > > bhelgaas@xxxxxxxxxx > > > > > Cc: linux-pci@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; > linux- > > > arm- > > > > > kernel@xxxxxxxxxxxxxxxxxxx; Jisheng Zhang > > > > > Subject: [PATCH v2] PCI: designware: move remaining rc setup > code > > > to > > > > > dw_pcie_setup_rc() > > > > > > > > > > dw_pcie_setup_rc(), as its name indicates, setups the RC. But > > > current > > > > > dw_pcie_host_init() also contains some necessary rc setup code. > > > > > > > > > > Another reason: the host may lost power during suspend to ram, > the > > > RC > > > > > need to be re-setup after resume. The rc can't be correctly > resumed > > > > > without the rc setup code in dw_pcie_host_init(). > > > > > > > > > > So this patch moves the code to dw_pcie_setup_rc() to address > the > > > above > > > > > two issues. After this patch, each pcie designware driver users > > > could > > > > > call dw_pcie_setup_rc() to re-setup rc when resume back. > > > > > > > > I think this patch breaks the Hisilicon driver... > > > > > > > > Our driver performs linkup setup in UEFI therefore we do not call > > > > dw_pcie_setup_rc(), we only call dw_pcie_host_init(). > > > > > > Thanks for the information. So pcie-hisi rely on UEFI to do > something > > > similar > > > in dw_pcie_setup_rc(), this comes to a common driver implement > > > question: should > > > linux device driver rely on bootloader to configure HW device? > > > > I don't see any issue with this... > > > > > > > > Is it acceptable that pcie-hisi adds a call to dw_pcie_setup_rc() > in > > > hisi_add_pcie_port()? > > > > I don't think so...that would try to overwrite what is already set by > > the bootloader; so it is wrong in principle and maybe it can lead to > > undefined behaviours... > > make sense! This commit is intend to re-setup the rc when waken from > s2ram (in > s2ram state, the host lost power) > > I have no good solution but to introduce one function e.g > dw_pcie_setup_rc_after_linkup(), then move related code from > dw_pcie_host_init > to it, then let my host driver resume hook to call. > > Hi Pratyush, Jingoo and Bjorn etc. > > any suggestions are appreciated! What about: diff --git a/drivers/pci/host/pcie-designware.c b/drivers/pci/host/pcie-designware.c index a4cccd3..e461f5d 100644 --- a/drivers/pci/host/pcie-designware.c +++ b/drivers/pci/host/pcie-designware.c @@ -434,7 +434,6 @@ int dw_pcie_host_init(struct pcie_port *pp) struct platform_device *pdev = to_platform_device(pp->dev); struct pci_bus *bus, *child; struct resource *cfg_res; - u32 val; int i, ret; LIST_HEAD(res); struct resource_entry *win; @@ -544,25 +543,6 @@ int dw_pcie_host_init(struct pcie_port *pp) if (pp->ops->host_init) pp->ops->host_init(pp); - /* - * If the platform provides ->rd_other_conf, it means the platform - * uses its own address translation component rather than ATU, so - * we should not program the ATU here. - */ - if (!pp->ops->rd_other_conf) - dw_pcie_prog_outbound_atu(pp, PCIE_ATU_REGION_INDEX1, - PCIE_ATU_TYPE_MEM, pp->mem_base, - pp->mem_bus_addr, pp->mem_size); - - dw_pcie_wr_own_conf(pp, PCI_BASE_ADDRESS_0, 4, 0); - - /* program correct class for RC */ - dw_pcie_wr_own_conf(pp, PCI_CLASS_DEVICE, 2, PCI_CLASS_BRIDGE_PCI); - - dw_pcie_rd_own_conf(pp, PCIE_LINK_WIDTH_SPEED_CONTROL, 4, &val); - val |= PORT_LOGIC_SPEED_CHANGE; - dw_pcie_wr_own_conf(pp, PCIE_LINK_WIDTH_SPEED_CONTROL, 4, val); - pp->root_bus_nr = pp->busn->start; if (IS_ENABLED(CONFIG_PCI_MSI)) { bus = pci_scan_root_bus_msi(pp->dev, pp->root_bus_nr, @@ -725,6 +705,29 @@ static struct pci_ops dw_pcie_ops = { .write = dw_pcie_wr_conf, }; +void dw_pcie_setup_own_cfg(struct pcie_port *pp) +{ + u32 val; + /* + * If the platform provides ->rd_other_conf, it means the platform + * uses its own address translation component rather than ATU, so + * we should not program the ATU here. + */ + if (!pp->ops->rd_other_conf) + dw_pcie_prog_outbound_atu(pp, PCIE_ATU_REGION_INDEX1, + PCIE_ATU_TYPE_MEM, pp->mem_base, + pp->mem_bus_addr, pp->mem_size); + + dw_pcie_wr_own_conf(pp, PCI_BASE_ADDRESS_0, 4, 0); + + /* program correct class for RC */ + dw_pcie_wr_own_conf(pp, PCI_CLASS_DEVICE, 2, PCI_CLASS_BRIDGE_PCI); + + dw_pcie_rd_own_conf(pp, PCIE_LINK_WIDTH_SPEED_CONTROL, 4, &val); + val |= PORT_LOGIC_SPEED_CHANGE; + dw_pcie_wr_own_conf(pp, PCIE_LINK_WIDTH_SPEED_CONTROL, 4, val); +} + void dw_pcie_setup_rc(struct pcie_port *pp) { u32 val; @@ -800,6 +803,8 @@ void dw_pcie_setup_rc(struct pcie_port *pp) val |= PCI_COMMAND_IO | PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER | PCI_COMMAND_SERR; dw_pcie_writel_rc(pp, val, PCI_COMMAND); + + dw_pcie_setup_own_cfg(pp); } MODULE_AUTHOR("Jingoo Han <jg1.han@xxxxxxxxxxx>"); diff --git a/drivers/pci/host/pcie-designware.h b/drivers/pci/host/pcie-designware.h index f437f9b..caf0f5d 100644 --- a/drivers/pci/host/pcie-designware.h +++ b/drivers/pci/host/pcie-designware.h @@ -85,5 +85,6 @@ int dw_pcie_wait_for_link(struct pcie_port *pp); int dw_pcie_link_up(struct pcie_port *pp); void dw_pcie_setup_rc(struct pcie_port *pp); int dw_pcie_host_init(struct pcie_port *pp); +void dw_pcie_setup_own_cfg(struct pcie_port *pp); #endif /* _PCIE_DESIGNWARE_H */ diff --git a/drivers/pci/host/pcie-hisi.c b/drivers/pci/host/pcie-hisi.c index 3e98d4e..8da29b2 100644 --- a/drivers/pci/host/pcie-hisi.c +++ b/drivers/pci/host/pcie-hisi.c @@ -164,6 +164,7 @@ static int hisi_add_pcie_port(struct pcie_port *pp, dev_err(&pdev->dev, "failed to initialize host\n"); return ret; } + dw_pcie_setup_own_cfg(pp); return 0; } > > Thanks, > Jisheng -- 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
