On Mon, 13 Jun 2022 at 02:29, Jason Lai <jasonlai.genesyslogic@xxxxxxxxx> wrote: > > From: Jason Lai <jasonlai.genesyslogic@xxxxxxxxx> > > To improve READ/WRITE performance and take battery life into account, we > turn on GL9763E L1 negotiation before entering runtime suspend and turn > off GL9763E L1 negotiation while executing runtime resume. That is to say, > GL9763E will not enter L1 state when executing I/O requests and enter L1 > state when PCIe bus idle. > > Signed-off-by: Renius Chen <reniuschengl@xxxxxxxxx> > Signed-off-by: Jason Lai <jason.lai@xxxxxxxxxxxxxxxxxxx> Applied for next, thanks! Kind regards Uffe > --- > > This patch is the follow-up to the patch [1] and adopt Ulf's comment. > > Due to flaws in hardware design, GL9763E takes long time to exit from L1 > state. The I/O performance will suffer severe impact if it often enter > and exit L1 state during I/O requests. > > [1] https://patchwork.kernel.org/project/linux-mmc/list/?series=646869 > > --- > drivers/mmc/host/sdhci-pci-gli.c | 34 ++++++++++++++++++++++++++++++++ > 1 file changed, 34 insertions(+) > > diff --git a/drivers/mmc/host/sdhci-pci-gli.c b/drivers/mmc/host/sdhci-pci-gli.c > index d09728c37d03..69bc3d614e15 100644 > --- a/drivers/mmc/host/sdhci-pci-gli.c > +++ b/drivers/mmc/host/sdhci-pci-gli.c > @@ -95,6 +95,9 @@ > #define PCIE_GLI_9763E_SCR 0x8E0 > #define GLI_9763E_SCR_AXI_REQ BIT(9) > > +#define PCIE_GLI_9763E_CFG 0x8A0 > +#define GLI_9763E_CFG_LPSN_DIS BIT(12) > + > #define PCIE_GLI_9763E_CFG2 0x8A4 > #define GLI_9763E_CFG2_L1DLY GENMASK(28, 19) > #define GLI_9763E_CFG2_L1DLY_MID 0x54 > @@ -818,6 +821,31 @@ static void sdhci_gl9763e_dumpregs(struct mmc_host *mmc) > sdhci_dumpregs(mmc_priv(mmc)); > } > > +static void gl9763e_set_low_power_negotiation(struct sdhci_pci_slot *slot, bool enable) > +{ > + struct pci_dev *pdev = slot->chip->pdev; > + u32 value; > + > + pci_read_config_dword(pdev, PCIE_GLI_9763E_VHS, &value); > + value &= ~GLI_9763E_VHS_REV; > + value |= FIELD_PREP(GLI_9763E_VHS_REV, GLI_9763E_VHS_REV_W); > + pci_write_config_dword(pdev, PCIE_GLI_9763E_VHS, value); > + > + pci_read_config_dword(pdev, PCIE_GLI_9763E_CFG, &value); > + > + if (enable) > + value &= ~GLI_9763E_CFG_LPSN_DIS; > + else > + value |= GLI_9763E_CFG_LPSN_DIS; > + > + pci_write_config_dword(pdev, PCIE_GLI_9763E_CFG, value); > + > + pci_read_config_dword(pdev, PCIE_GLI_9763E_VHS, &value); > + value &= ~GLI_9763E_VHS_REV; > + value |= FIELD_PREP(GLI_9763E_VHS_REV, GLI_9763E_VHS_REV_R); > + pci_write_config_dword(pdev, PCIE_GLI_9763E_VHS, value); > +} > + > static void sdhci_gl9763e_cqe_pre_enable(struct mmc_host *mmc) > { > struct cqhci_host *cq_host = mmc->cqe_private; > @@ -959,6 +987,9 @@ static int gl9763e_runtime_suspend(struct sdhci_pci_chip *chip) > struct sdhci_host *host = slot->host; > u16 clock; > > + /* Enable LPM negotiation to allow entering L1 state */ > + gl9763e_set_low_power_negotiation(slot, true); > + > clock = sdhci_readw(host, SDHCI_CLOCK_CONTROL); > clock &= ~(SDHCI_CLOCK_PLL_EN | SDHCI_CLOCK_CARD_EN); > sdhci_writew(host, clock, SDHCI_CLOCK_CONTROL); > @@ -989,6 +1020,9 @@ static int gl9763e_runtime_resume(struct sdhci_pci_chip *chip) > clock |= SDHCI_CLOCK_CARD_EN; > sdhci_writew(host, clock, SDHCI_CLOCK_CONTROL); > > + /* Disable LPM negotiation to avoid entering L1 state. */ > + gl9763e_set_low_power_negotiation(slot, false); > + > return 0; > } > #endif > -- > 2.36.1 >
