To improve the r/w performance of GL9763E, the current driver inhibits LPM negotiation while the device is active.

This prevents a large number of SoCs from suspending, notably x86 systems which use S0ix as the suspend mechanism: 1. Userspace initiates s2idle suspend (e.g. via writing to /sys/power/state) 2. This switches the runtime_pm device state to active, which disables LPM negotiation, then calls the "regular" suspend callback 3. With LPM negotiation disabled, the bus cannot enter low-power state 4. On a large number of SoCs, if the bus not in a low-power state, S0ix cannot be entered, which in turn prevents the SoC from entering suspend.

Fix by re-enabling LPM negotiation in the device's suspend callback.

Suggested-by: Stanislaw Kardach skardach@google.com Fixes: f9e5b33934ce ("mmc: host: Improve I/O read/write performance for GL9763E") Cc: stable@vger.kernel.org Signed-off-by: Sven van Ashbrook svenva@chromium.org ---

drivers/mmc/host/sdhci-pci-gli.c | 96 +++++++++++++++++++------------- 1 file changed, 58 insertions(+), 38 deletions(-)

diff --git a/drivers/mmc/host/sdhci-pci-gli.c b/drivers/mmc/host/sdhci-pci-gli.c index 1792665c9494a..bc148276cc001 100644 --- a/drivers/mmc/host/sdhci-pci-gli.c +++ b/drivers/mmc/host/sdhci-pci-gli.c @@ -745,42 +745,6 @@ static u32 sdhci_gl9750_readl(struct sdhci_host *host, int reg) return value; }

-#ifdef CONFIG_PM_SLEEP -static int sdhci_pci_gli_resume(struct sdhci_pci_chip *chip) -{ - struct sdhci_pci_slot *slot = chip->slots[0]; - - pci_free_irq_vectors(slot->chip->pdev); - gli_pcie_enable_msi(slot); - - return sdhci_pci_resume_host(chip); -} - -static int sdhci_cqhci_gli_resume(struct sdhci_pci_chip *chip) -{ - struct sdhci_pci_slot *slot = chip->slots[0]; - int ret; - - ret = sdhci_pci_gli_resume(chip); - if (ret) - return ret; - - return cqhci_resume(slot->host->mmc); -} - -static int sdhci_cqhci_gli_suspend(struct sdhci_pci_chip *chip) -{ - struct sdhci_pci_slot *slot = chip->slots[0]; - int ret; - - ret = cqhci_suspend(slot->host->mmc); - if (ret) - return ret; - - return sdhci_suspend_host(slot->host); -} -#endif - static void gl9763e_hs400_enhanced_strobe(struct mmc_host *mmc, struct mmc_ios *ios) { @@ -1029,6 +993,62 @@ static int gl9763e_runtime_resume(struct sdhci_pci_chip *chip) } #endif

+#ifdef CONFIG_PM_SLEEP +static int sdhci_pci_gli_resume(struct sdhci_pci_chip *chip) +{ + struct sdhci_pci_slot *slot = chip->slots[0]; + + pci_free_irq_vectors(slot->chip->pdev); + gli_pcie_enable_msi(slot); + + return sdhci_pci_resume_host(chip); +} + +static int gl9763e_resume(struct sdhci_pci_chip *chip) +{ + struct sdhci_pci_slot *slot = chip->slots[0]; + int ret; + + ret = sdhci_pci_gli_resume(chip); + if (ret) + return ret; + + ret = cqhci_resume(slot->host->mmc); + if (ret) + return ret; + + /* Disable LPM negotiation to bring device back in sync + * with its runtime_pm state. + */ + gl9763e_set_low_power_negotiation(slot, false); + + return 0; +} + +static int gl9763e_suspend(struct sdhci_pci_chip *chip) +{ + struct sdhci_pci_slot *slot = chip->slots[0]; + int ret; + + ret = cqhci_suspend(slot->host->mmc); + if (ret) + return ret; + + ret = sdhci_suspend_host(slot->host); + if (ret) + return ret; + + /* Certain SoCs can suspend only with the bus in low- + * power state, notably x86 SoCs when using S0ix. + * Re-enable LPM negotiation to allow entering L1 state + * and entering system suspend. + */ + gl9763e_set_low_power_negotiation(slot, true); + + return 0; +} +#endif + static int gli_probe_slot_gl9763e(struct sdhci_pci_slot *slot) { struct pci_dev *pdev = slot->chip->pdev; @@ -1113,8 +1133,8 @@ const struct sdhci_pci_fixes sdhci_gl9763e = { .probe_slot = gli_probe_slot_gl9763e, .ops = &sdhci_gl9763e_ops, #ifdef CONFIG_PM_SLEEP - .resume = sdhci_cqhci_gli_resume, - .suspend = sdhci_cqhci_gli_suspend, + .resume = gl9763e_resume, + .suspend = gl9763e_suspend, #endif #ifdef CONFIG_PM .runtime_suspend = gl9763e_runtime_suspend,