On 14/11/23 13:54, Kornel Dulęba wrote:
> To address IO performance commit f9e5b33934ce
> ("mmc: host: Improve I/O read/write performance for GL9763E")
> limited LPM negotiation to runtime suspend state.
> The problem is that it only flips the switch in the runtime PM
> resume/suspend logic.
>
> Disable LPM negotiation in gl9763e_add_host.
> This helps in two ways:
> 1. It was found that the LPM switch stays in the same position after
> warm reboot. Having it set in init helps with consistency.
> 2. Disabling LPM during the first runtime resume leaves us susceptible
> to the performance issue in the time window between boot and the
> first runtime suspend.
>
> Fixes: f9e5b33934ce ("mmc: host: Improve I/O read/write performance for GL9763E")
> Cc: [email protected]
> Signed-off-by: Kornel Dulęba <[email protected]>
Acked-by: Adrian Hunter <[email protected]>
> ---
> v2: Move up gl9763e_set_low_power_negotiation to avoid having to forward
> declare it.
>
> drivers/mmc/host/sdhci-pci-gli.c | 54 +++++++++++++++++---------------
> 1 file changed, 29 insertions(+), 25 deletions(-)
>
> diff --git a/drivers/mmc/host/sdhci-pci-gli.c b/drivers/mmc/host/sdhci-pci-gli.c
> index d8a991b349a8..77911a57b12c 100644
> --- a/drivers/mmc/host/sdhci-pci-gli.c
> +++ b/drivers/mmc/host/sdhci-pci-gli.c
> @@ -1189,6 +1189,32 @@ static void gl9763e_hs400_enhanced_strobe(struct mmc_host *mmc,
> sdhci_writel(host, val, SDHCI_GLI_9763E_HS400_ES_REG);
> }
>
> +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_set_gl9763e_signaling(struct sdhci_host *host,
> unsigned int timing)
> {
> @@ -1297,6 +1323,9 @@ static int gl9763e_add_host(struct sdhci_pci_slot *slot)
> if (ret)
> goto cleanup;
>
> + /* Disable LPM negotiation to avoid entering L1 state. */
> + gl9763e_set_low_power_negotiation(slot, false);
> +
> return 0;
>
> cleanup:
> @@ -1340,31 +1369,6 @@ static void gli_set_gl9763e(struct sdhci_pci_slot *slot)
> }
>
> #ifdef CONFIG_PM
> -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 int gl9763e_runtime_suspend(struct sdhci_pci_chip *chip)
> {
> struct sdhci_pci_slot *slot = chip->slots[0];