* [PATCH v7 1/2] PCI: dwc: Implement general suspend/resume functionality for L2/L3 transitions @ 2023-08-02 15:57 Frank Li 2023-08-02 15:57 ` [PATCH v7 2/2] PCI: layerscape: Add power management support for ls1028a Frank Li 2023-08-02 16:31 ` [PATCH v7 1/2] PCI: dwc: Implement general suspend/resume functionality for L2/L3 transitions Bjorn Helgaas 0 siblings, 2 replies; 5+ messages in thread From: Frank Li @ 2023-08-02 15:57 UTC (permalink / raw) To: mani Cc: Frank.Li, bhelgaas, devicetree, gustavo.pimentel, helgaas, imx, kw, leoyang.li, linux-arm-kernel, linux-imx, linux-kernel, linux-pci, lorenzo.pieralisi, lpieralisi, manivannan.sadhasivam, minghuan.lian, mingkai.hu, robh+dt, roy.zang, shawnguo, zhiqiang.hou Introduce helper function dw_pcie_get_ltssm to retrieve SMLH_LTSS_STATE. Add callback .pme_turn_off and .exit_from_l2 for platform specific PME handling. Add common dw_pcie_suspend(resume)_noirq() API to avoid duplicated code in dwc pci host controller platform driver. Typical L2 entry workflow/dw_pcie_suspend_noirq() 1. Transmit PME turn off signal to PCI devices and wait for PME_To_Ack. 2. Await link entering L2_IDLE state. Typical L2 exit workflow/dw_pcie_resume_noirq() 1. Issue exit from L2 command. 2. Reinitialize PCI host. 3. Wait for link to become active. Signed-off-by: Frank Li <Frank.Li@nxp.com> --- Change from v6 to v7 - change according to Manivannan's comments. fix sleep value 100 (should be 1000 for 1ms). use dev_err when timeout Change from v5 to v6: - refine commit message change according to Manivannan's comments. - remove reduncate step dw_pcie_set_dstate() - return 0 when .pme_turn_off is zero - call host_deinit() in suspend - check .host_deinit and .host_init point before call. Change from v4 to v5: - Closes: https://lore.kernel.org/oe-kbuild-all/202307211904.zExw4Q8H-lkp@intel.com/ Change from v3 to v4: - change according to Manivannan's comments. I hope I have not missed anything. quite long discuss thread Change from v2 to v3: - Basic rewrite whole patch according rob herry suggestion. put common function into dwc, so more soc can share the same logic. .../pci/controller/dwc/pcie-designware-host.c | 78 +++++++++++++++++++ drivers/pci/controller/dwc/pcie-designware.h | 28 +++++++ 2 files changed, 106 insertions(+) diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c b/drivers/pci/controller/dwc/pcie-designware-host.c index 9952057c8819c..bc01ecc1c3ec8 100644 --- a/drivers/pci/controller/dwc/pcie-designware-host.c +++ b/drivers/pci/controller/dwc/pcie-designware-host.c @@ -8,6 +8,7 @@ * Author: Jingoo Han <jg1.han@samsung.com> */ +#include <linux/iopoll.h> #include <linux/irqchip/chained_irq.h> #include <linux/irqdomain.h> #include <linux/msi.h> @@ -807,3 +808,80 @@ int dw_pcie_setup_rc(struct dw_pcie_rp *pp) return 0; } EXPORT_SYMBOL_GPL(dw_pcie_setup_rc); + +int dw_pcie_suspend_noirq(struct dw_pcie *pci) +{ + u8 offset = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP); + u32 val; + int ret; + + /* + * If L1SS is supported, then do not put the link into L2 as some + * devices such as NVMe expect low resume latency. + */ + if (dw_pcie_readw_dbi(pci, offset + PCI_EXP_LNKCTL) & PCI_EXP_LNKCTL_ASPM_L1) + return 0; + + if (dw_pcie_get_ltssm(pci) <= DW_PCIE_LTSSM_DETECT_ACT) + return 0; + + if (!pci->pp.ops->pme_turn_off) + return 0; + + pci->pp.ops->pme_turn_off(&pci->pp); + + /* + * PCI Express Base Specification Rev 4.0 Section 5.3.3.2.1 PME + * Synchronization Recommends 1ms to 10ms timeout to check L2 ready. + */ + ret = read_poll_timeout(dw_pcie_get_ltssm, val, val == DW_PCIE_LTSSM_L2_IDLE, + 1000, 10000, false, pci); + if (ret) { + dev_err(pci->dev, "Timeout waiting for L2 entry! LTSSM: 0x%x\n", val); + return ret; + } + + if (pci->pp.ops->host_deinit) + pci->pp.ops->host_deinit(&pci->pp); + + pci->suspended = true; + + return ret; +} +EXPORT_SYMBOL_GPL(dw_pcie_suspend_noirq); + +int dw_pcie_resume_noirq(struct dw_pcie *pci) +{ + int ret; + + if (!pci->suspended) + return 0; + + pci->suspended = false; + + if (!pci->pp.ops->exit_from_l2) + return 0; + + pci->pp.ops->exit_from_l2(&pci->pp); + + if (pci->pp.ops->host_init) { + ret = pci->pp.ops->host_init(&pci->pp); + if (ret) { + dev_err(pci->dev, "Host init failed! ret = %d\n", ret); + return ret; + } + } + + dw_pcie_setup_rc(&pci->pp); + + ret = dw_pcie_start_link(pci); + if (ret) + return ret; + + ret = dw_pcie_wait_for_link(pci); + if (ret) + return ret; + + return ret; +} +EXPORT_SYMBOL_GPL(dw_pcie_resume_noirq); diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h index 79713ce075cc1..cbba3ed19b3c0 100644 --- a/drivers/pci/controller/dwc/pcie-designware.h +++ b/drivers/pci/controller/dwc/pcie-designware.h @@ -288,10 +288,21 @@ enum dw_pcie_core_rst { DW_PCIE_NUM_CORE_RSTS }; +enum dw_pcie_ltssm { + DW_PCIE_LTSSM_UNKNOWN = 0xFFFFFFFF, + /* Need to align with PCIE_PORT_DEBUG0 bits 0:5 */ + DW_PCIE_LTSSM_DETECT_QUIET = 0x0, + DW_PCIE_LTSSM_DETECT_ACT = 0x1, + DW_PCIE_LTSSM_L0 = 0x11, + DW_PCIE_LTSSM_L2_IDLE = 0x15, +}; + struct dw_pcie_host_ops { int (*host_init)(struct dw_pcie_rp *pp); void (*host_deinit)(struct dw_pcie_rp *pp); int (*msi_host_init)(struct dw_pcie_rp *pp); + void (*pme_turn_off)(struct dw_pcie_rp *pp); + void (*exit_from_l2)(struct dw_pcie_rp *pp); }; struct dw_pcie_rp { @@ -364,6 +375,7 @@ struct dw_pcie_ops { void (*write_dbi2)(struct dw_pcie *pcie, void __iomem *base, u32 reg, size_t size, u32 val); int (*link_up)(struct dw_pcie *pcie); + enum dw_pcie_ltssm (*get_ltssm)(struct dw_pcie *pcie); int (*start_link)(struct dw_pcie *pcie); void (*stop_link)(struct dw_pcie *pcie); }; @@ -393,6 +405,7 @@ struct dw_pcie { struct reset_control_bulk_data app_rsts[DW_PCIE_NUM_APP_RSTS]; struct reset_control_bulk_data core_rsts[DW_PCIE_NUM_CORE_RSTS]; struct gpio_desc *pe_rst; + bool suspended; }; #define to_dw_pcie_from_pp(port) container_of((port), struct dw_pcie, pp) @@ -430,6 +443,9 @@ void dw_pcie_iatu_detect(struct dw_pcie *pci); int dw_pcie_edma_detect(struct dw_pcie *pci); void dw_pcie_edma_remove(struct dw_pcie *pci); +int dw_pcie_suspend_noirq(struct dw_pcie *pci); +int dw_pcie_resume_noirq(struct dw_pcie *pci); + static inline void dw_pcie_writel_dbi(struct dw_pcie *pci, u32 reg, u32 val) { dw_pcie_write_dbi(pci, reg, 0x4, val); @@ -501,6 +517,18 @@ static inline void dw_pcie_stop_link(struct dw_pcie *pci) pci->ops->stop_link(pci); } +static inline enum dw_pcie_ltssm dw_pcie_get_ltssm(struct dw_pcie *pci) +{ + u32 val; + + if (pci->ops && pci->ops->get_ltssm) + return pci->ops->get_ltssm(pci); + + val = dw_pcie_readl_dbi(pci, PCIE_PORT_DEBUG0); + + return (enum dw_pcie_ltssm)FIELD_GET(PORT_LOGIC_LTSSM_STATE_MASK, val); +} + #ifdef CONFIG_PCIE_DW_HOST irqreturn_t dw_handle_msi_irq(struct dw_pcie_rp *pp); int dw_pcie_setup_rc(struct dw_pcie_rp *pp); -- 2.34.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel ^ permalink raw reply related [flat|nested] 5+ messages in thread
* [PATCH v7 2/2] PCI: layerscape: Add power management support for ls1028a 2023-08-02 15:57 [PATCH v7 1/2] PCI: dwc: Implement general suspend/resume functionality for L2/L3 transitions Frank Li @ 2023-08-02 15:57 ` Frank Li 2023-08-02 16:31 ` [PATCH v7 1/2] PCI: dwc: Implement general suspend/resume functionality for L2/L3 transitions Bjorn Helgaas 1 sibling, 0 replies; 5+ messages in thread From: Frank Li @ 2023-08-02 15:57 UTC (permalink / raw) To: mani Cc: Frank.Li, bhelgaas, devicetree, gustavo.pimentel, helgaas, imx, kw, leoyang.li, linux-arm-kernel, linux-imx, linux-kernel, linux-pci, lorenzo.pieralisi, lpieralisi, manivannan.sadhasivam, minghuan.lian, mingkai.hu, robh+dt, roy.zang, shawnguo, zhiqiang.hou From: Hou Zhiqiang <Zhiqiang.Hou@nxp.com> Add PME_Turn_off/PME_TO_Ack handshake sequence for ls1028a platform. Call common dwc dw_pcie_suspend(resume)_noirq() function when system enter/exit suspend state. Signed-off-by: Hou Zhiqiang <Zhiqiang.Hou@nxp.com> Signed-off-by: Frank Li <Frank.Li@nxp.com> --- - Chnage from v6 to v7 Remove local varible struct dw_pcie *pci = pcie->pci Change according to Manivannan's feedback remove unused lut_off and lut_base fixed 100 to 1000(for 1ms) using dev_err for timeout refine commit message - Change from v5 to v6 change to NOIRQ_SYSTEM_SLEEP_PM_OPS to remove #ifdef PM_CONFIG - Change from v3 to v5 none - change at v3 Basic rewrite whole patch according rob herry suggestion. put common function into dwc, so more soc can share the same logic. drivers/pci/controller/dwc/pci-layerscape.c | 125 ++++++++++++++++++-- 1 file changed, 116 insertions(+), 9 deletions(-) diff --git a/drivers/pci/controller/dwc/pci-layerscape.c b/drivers/pci/controller/dwc/pci-layerscape.c index ed5fb492fe084..80d0327d4ec7b 100644 --- a/drivers/pci/controller/dwc/pci-layerscape.c +++ b/drivers/pci/controller/dwc/pci-layerscape.c @@ -8,9 +8,11 @@ * Author: Minghuan Lian <Minghuan.Lian@freescale.com> */ +#include <linux/delay.h> #include <linux/kernel.h> #include <linux/interrupt.h> #include <linux/init.h> +#include <linux/iopoll.h> #include <linux/of_pci.h> #include <linux/of_platform.h> #include <linux/of_address.h> @@ -27,12 +29,26 @@ #define PCIE_ABSERR 0x8d0 /* Bridge Slave Error Response Register */ #define PCIE_ABSERR_SETTING 0x9401 /* Forward error of non-posted request */ +/* PF Message Command Register */ +#define LS_PCIE_PF_MCR 0x2c +#define PF_MCR_PTOMR BIT(0) +#define PF_MCR_EXL2S BIT(1) + #define PCIE_IATU_NUM 6 +struct ls_pcie_drvdata { + const u32 pf_off; + bool pm_support; +}; + struct ls_pcie { struct dw_pcie *pci; + const struct ls_pcie_drvdata *drvdata; + void __iomem *pf_base; + bool big_endian; }; +#define ls_pcie_pf_readl_addr(addr) ls_pcie_pf_readl(pcie, addr) #define to_ls_pcie(x) dev_get_drvdata((x)->dev) static bool ls_pcie_is_bridge(struct ls_pcie *pcie) @@ -73,6 +89,56 @@ static void ls_pcie_fix_error_response(struct ls_pcie *pcie) iowrite32(PCIE_ABSERR_SETTING, pci->dbi_base + PCIE_ABSERR); } +static u32 ls_pcie_pf_readl(struct ls_pcie *pcie, u32 off) +{ + if (pcie->big_endian) + return ioread32be(pcie->pf_base + off); + + return ioread32(pcie->pf_base + off); +} + +static void ls_pcie_pf_writel(struct ls_pcie *pcie, u32 off, u32 val) +{ + if (pcie->big_endian) + iowrite32be(val, pcie->pf_base + off); + else + iowrite32(val, pcie->pf_base + off); +} + +static void ls_pcie_send_turnoff_msg(struct dw_pcie_rp *pp) +{ + struct dw_pcie *pci = to_dw_pcie_from_pp(pp); + struct ls_pcie *pcie = to_ls_pcie(pci); + u32 val; + int ret; + + val = ls_pcie_pf_readl(pcie, LS_PCIE_PF_MCR); + val |= PF_MCR_PTOMR; + ls_pcie_pf_writel(pcie, LS_PCIE_PF_MCR, val); + + ret = readx_poll_timeout(ls_pcie_pf_readl_addr, LS_PCIE_PF_MCR, + val, !(val & PF_MCR_PTOMR), 1000, 10000); + if (ret) + dev_err(pcie->pci->dev, "poll turn off message timeout\n"); +} + +static void ls_pcie_exit_from_l2(struct dw_pcie_rp *pp) +{ + struct dw_pcie *pci = to_dw_pcie_from_pp(pp); + struct ls_pcie *pcie = to_ls_pcie(pci); + u32 val; + int ret; + + val = ls_pcie_pf_readl(pcie, LS_PCIE_PF_MCR); + val |= PF_MCR_EXL2S; + ls_pcie_pf_writel(pcie, LS_PCIE_PF_MCR, val); + + ret = readx_poll_timeout(ls_pcie_pf_readl_addr, LS_PCIE_PF_MCR, + val, !(val & PF_MCR_EXL2S), 1000, 10000); + if (ret) + dev_err(pcie->pci->dev, "poll exit L2 state timeout\n"); +} + static int ls_pcie_host_init(struct dw_pcie_rp *pp) { struct dw_pcie *pci = to_dw_pcie_from_pp(pp); @@ -91,18 +157,28 @@ static int ls_pcie_host_init(struct dw_pcie_rp *pp) static const struct dw_pcie_host_ops ls_pcie_host_ops = { .host_init = ls_pcie_host_init, + .pme_turn_off = ls_pcie_send_turnoff_msg, + .exit_from_l2 = ls_pcie_exit_from_l2, +}; + +static const struct ls_pcie_drvdata ls1021a_drvdata = { +}; + +static const struct ls_pcie_drvdata layerscape_drvdata = { + .pf_off = 0xc0000, + .pm_support = true, }; static const struct of_device_id ls_pcie_of_match[] = { - { .compatible = "fsl,ls1012a-pcie", }, - { .compatible = "fsl,ls1021a-pcie", }, - { .compatible = "fsl,ls1028a-pcie", }, - { .compatible = "fsl,ls1043a-pcie", }, - { .compatible = "fsl,ls1046a-pcie", }, - { .compatible = "fsl,ls2080a-pcie", }, - { .compatible = "fsl,ls2085a-pcie", }, - { .compatible = "fsl,ls2088a-pcie", }, - { .compatible = "fsl,ls1088a-pcie", }, + { .compatible = "fsl,ls1012a-pcie", .data = &layerscape_drvdata }, + { .compatible = "fsl,ls1021a-pcie", .data = &ls1021a_drvdata }, + { .compatible = "fsl,ls1028a-pcie", .data = &layerscape_drvdata }, + { .compatible = "fsl,ls1043a-pcie", .data = &ls1021a_drvdata }, + { .compatible = "fsl,ls1046a-pcie", .data = &layerscape_drvdata }, + { .compatible = "fsl,ls2080a-pcie", .data = &layerscape_drvdata }, + { .compatible = "fsl,ls2085a-pcie", .data = &layerscape_drvdata }, + { .compatible = "fsl,ls2088a-pcie", .data = &layerscape_drvdata }, + { .compatible = "fsl,ls1088a-pcie", .data = &layerscape_drvdata }, { }, }; @@ -121,6 +197,8 @@ static int ls_pcie_probe(struct platform_device *pdev) if (!pci) return -ENOMEM; + pcie->drvdata = of_device_get_match_data(dev); + pci->dev = dev; pci->pp.ops = &ls_pcie_host_ops; @@ -131,6 +209,10 @@ static int ls_pcie_probe(struct platform_device *pdev) if (IS_ERR(pci->dbi_base)) return PTR_ERR(pci->dbi_base); + pcie->big_endian = of_property_read_bool(dev->of_node, "big-endian"); + + pcie->pf_base = pci->dbi_base + pcie->drvdata->pf_off; + if (!ls_pcie_is_bridge(pcie)) return -ENODEV; @@ -139,12 +221,37 @@ static int ls_pcie_probe(struct platform_device *pdev) return dw_pcie_host_init(&pci->pp); } +static int ls_pcie_suspend_noirq(struct device *dev) +{ + struct ls_pcie *pcie = dev_get_drvdata(dev); + + if (!pcie->drvdata->pm_support) + return 0; + + return dw_pcie_suspend_noirq(pcie->pci); +} + +static int ls_pcie_resume_noirq(struct device *dev) +{ + struct ls_pcie *pcie = dev_get_drvdata(dev); + + if (!pcie->drvdata->pm_support) + return 0; + + return dw_pcie_resume_noirq(pcie->pci); +} + +static const struct dev_pm_ops ls_pcie_pm_ops = { + NOIRQ_SYSTEM_SLEEP_PM_OPS(ls_pcie_suspend_noirq, ls_pcie_resume_noirq) +}; + static struct platform_driver ls_pcie_driver = { .probe = ls_pcie_probe, .driver = { .name = "layerscape-pcie", .of_match_table = ls_pcie_of_match, .suppress_bind_attrs = true, + .pm = &ls_pcie_pm_ops, }, }; builtin_platform_driver(ls_pcie_driver); -- 2.34.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel ^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH v7 1/2] PCI: dwc: Implement general suspend/resume functionality for L2/L3 transitions 2023-08-02 15:57 [PATCH v7 1/2] PCI: dwc: Implement general suspend/resume functionality for L2/L3 transitions Frank Li 2023-08-02 15:57 ` [PATCH v7 2/2] PCI: layerscape: Add power management support for ls1028a Frank Li @ 2023-08-02 16:31 ` Bjorn Helgaas 2023-08-02 18:44 ` Frank Li 1 sibling, 1 reply; 5+ messages in thread From: Bjorn Helgaas @ 2023-08-02 16:31 UTC (permalink / raw) To: Frank Li Cc: mani, bhelgaas, devicetree, gustavo.pimentel, imx, kw, leoyang.li, linux-arm-kernel, linux-imx, linux-kernel, linux-pci, lorenzo.pieralisi, lpieralisi, manivannan.sadhasivam, minghuan.lian, mingkai.hu, robh+dt, roy.zang, shawnguo, zhiqiang.hou On Wed, Aug 02, 2023 at 11:57:47AM -0400, Frank Li wrote: > Introduce helper function dw_pcie_get_ltssm to retrieve SMLH_LTSS_STATE. s/dw_pcie_get_ltssm/dw_pcie_get_ltssm()/ > Add callback .pme_turn_off and .exit_from_l2 for platform specific PME > handling. > > Add common dw_pcie_suspend(resume)_noirq() API to avoid duplicated code > in dwc pci host controller platform driver. > > Typical L2 entry workflow/dw_pcie_suspend_noirq() > > 1. Transmit PME turn off signal to PCI devices and wait for PME_To_Ack. > 2. Await link entering L2_IDLE state. > > Typical L2 exit workflow/dw_pcie_resume_noirq() > > 1. Issue exit from L2 command. > 2. Reinitialize PCI host. > 3. Wait for link to become active. > > Signed-off-by: Frank Li <Frank.Li@nxp.com> > --- > Change from v6 to v7 > - change according to Manivannan's comments. > fix sleep value 100 (should be 1000 for 1ms). > + * PCI Express Base Specification Rev 4.0 Section 5.3.3.2.1 PME > + * Synchronization Recommends 1ms to 10ms timeout to check L2 ready. > + */ > + ret = read_poll_timeout(dw_pcie_get_ltssm, val, val == DW_PCIE_LTSSM_L2_IDLE, > + 1000, 10000, false, pci); Thanks for the spec citation. Can you please reference the current spec, i.e., "PCIe r6.0, sec 5.3.3.2.1". s/Recommends/recommends/ It would really be great to have a #define for this since the bare numbers are not very meaningful and they're not specific to DWC so a #define would let us find similar situations in other drivers. Bjorn _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH v7 1/2] PCI: dwc: Implement general suspend/resume functionality for L2/L3 transitions 2023-08-02 16:31 ` [PATCH v7 1/2] PCI: dwc: Implement general suspend/resume functionality for L2/L3 transitions Bjorn Helgaas @ 2023-08-02 18:44 ` Frank Li 2023-08-02 19:06 ` Bjorn Helgaas 0 siblings, 1 reply; 5+ messages in thread From: Frank Li @ 2023-08-02 18:44 UTC (permalink / raw) To: Bjorn Helgaas Cc: mani, bhelgaas, devicetree, gustavo.pimentel, imx, kw, leoyang.li, linux-arm-kernel, linux-imx, linux-kernel, linux-pci, lorenzo.pieralisi, lpieralisi, manivannan.sadhasivam, minghuan.lian, mingkai.hu, robh+dt, roy.zang, shawnguo, zhiqiang.hou On Wed, Aug 02, 2023 at 11:31:38AM -0500, Bjorn Helgaas wrote: > On Wed, Aug 02, 2023 at 11:57:47AM -0400, Frank Li wrote: > > Introduce helper function dw_pcie_get_ltssm to retrieve SMLH_LTSS_STATE. > > s/dw_pcie_get_ltssm/dw_pcie_get_ltssm()/ > > > Add callback .pme_turn_off and .exit_from_l2 for platform specific PME > > handling. > > > > Add common dw_pcie_suspend(resume)_noirq() API to avoid duplicated code > > in dwc pci host controller platform driver. > > > > Typical L2 entry workflow/dw_pcie_suspend_noirq() > > > > 1. Transmit PME turn off signal to PCI devices and wait for PME_To_Ack. > > 2. Await link entering L2_IDLE state. > > > > Typical L2 exit workflow/dw_pcie_resume_noirq() > > > > 1. Issue exit from L2 command. > > 2. Reinitialize PCI host. > > 3. Wait for link to become active. > > > > Signed-off-by: Frank Li <Frank.Li@nxp.com> > > --- > > Change from v6 to v7 > > - change according to Manivannan's comments. > > fix sleep value 100 (should be 1000 for 1ms). > > > + * PCI Express Base Specification Rev 4.0 Section 5.3.3.2.1 PME > > + * Synchronization Recommends 1ms to 10ms timeout to check L2 ready. > > + */ > > + ret = read_poll_timeout(dw_pcie_get_ltssm, val, val == DW_PCIE_LTSSM_L2_IDLE, > > + 1000, 10000, false, pci); > > Thanks for the spec citation. Can you please reference the current > spec, i.e., "PCIe r6.0, sec 5.3.3.2.1". > > s/Recommends/recommends/ > > It would really be great to have a #define for this since the bare > numbers are not very meaningful and they're not specific to DWC so a > #define would let us find similar situations in other drivers. how about define as #define PCI_PME_TO_L2_TIMEOUT 10000 ret = read_poll_timeout(dw_pcie_get_ltssm, val, val == DW_PCIE_LTSSM_L2_IDLE, PCI_PME_TO_L2_TIMEOUT/10, PCI_PME_TO_L2_TIMEOUT, false, pci); where is good place PCI_PME_TO_L2_TIMEOUT in? pcie-designware.h or pci.h? Frank > > Bjorn _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH v7 1/2] PCI: dwc: Implement general suspend/resume functionality for L2/L3 transitions 2023-08-02 18:44 ` Frank Li @ 2023-08-02 19:06 ` Bjorn Helgaas 0 siblings, 0 replies; 5+ messages in thread From: Bjorn Helgaas @ 2023-08-02 19:06 UTC (permalink / raw) To: Frank Li Cc: mani, bhelgaas, devicetree, gustavo.pimentel, imx, kw, leoyang.li, linux-arm-kernel, linux-imx, linux-kernel, linux-pci, lorenzo.pieralisi, lpieralisi, manivannan.sadhasivam, minghuan.lian, mingkai.hu, robh+dt, roy.zang, shawnguo, zhiqiang.hou On Wed, Aug 02, 2023 at 02:44:52PM -0400, Frank Li wrote: > On Wed, Aug 02, 2023 at 11:31:38AM -0500, Bjorn Helgaas wrote: > > On Wed, Aug 02, 2023 at 11:57:47AM -0400, Frank Li wrote: > > > Introduce helper function dw_pcie_get_ltssm to retrieve SMLH_LTSS_STATE. > > > Add callback .pme_turn_off and .exit_from_l2 for platform specific PME > > > handling. > > > + * PCI Express Base Specification Rev 4.0 Section 5.3.3.2.1 PME > > > + * Synchronization Recommends 1ms to 10ms timeout to check L2 ready. > > > + */ > > > + ret = read_poll_timeout(dw_pcie_get_ltssm, val, val == DW_PCIE_LTSSM_L2_IDLE, > > > + 1000, 10000, false, pci); > > It would really be great to have a #define for this since the bare > > numbers are not very meaningful and they're not specific to DWC so a > > #define would let us find similar situations in other drivers. > > how about define as > > #define PCI_PME_TO_L2_TIMEOUT 10000 > > ret = read_poll_timeout(dw_pcie_get_ltssm, val, val == DW_PCIE_LTSSM_L2_IDLE, > PCI_PME_TO_L2_TIMEOUT/10, PCI_PME_TO_L2_TIMEOUT, false, pci); > > where is good place PCI_PME_TO_L2_TIMEOUT in? > > pcie-designware.h or pci.h? I think drivers/pci/pci.h since it's only useful inside drivers/pci, and it's not specific to dwc. Maybe "PCIE_" (not "PCI_") since this is a PCIe-specific thing. You could put it next to PCIE_LINK_RETRAIN_TIMEOUT_MS and add a "_US" suffix so we know what the units are. Bjorn _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel ^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2023-08-02 19:06 UTC | newest] Thread overview: 5+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2023-08-02 15:57 [PATCH v7 1/2] PCI: dwc: Implement general suspend/resume functionality for L2/L3 transitions Frank Li 2023-08-02 15:57 ` [PATCH v7 2/2] PCI: layerscape: Add power management support for ls1028a Frank Li 2023-08-02 16:31 ` [PATCH v7 1/2] PCI: dwc: Implement general suspend/resume functionality for L2/L3 transitions Bjorn Helgaas 2023-08-02 18:44 ` Frank Li 2023-08-02 19:06 ` Bjorn Helgaas
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