Commit d9ed644f authored by Kornel Dulęba's avatar Kornel Dulęba Committed by Ulf Hansson
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mmc: sdhci-pci-gli: Disable LPM during initialization 



To address IO performance commit f9e5b339
("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: f9e5b339 ("mmc: host: Improve I/O read/write performance for GL9763E")
Cc: stable@vger.kernel.org
Signed-off-by: default avatarKornel Dulęba <korneld@chromium.org>
Reviewed-by: default avatarSven van Ashbrook <svenva@chromium.org>
Acked-by: default avatarAdrian Hunter <adrian.hunter@intel.com>
Link: https://lore.kernel.org/r/20231114115516.1585361-1-korneld@chromium.org


Signed-off-by: default avatarUlf Hansson <ulf.hansson@linaro.org>
parent 1de1b779

drivers/mmc/host/sdhci-pci-gli.c

+29 −25
Original line number Diff line number Diff line
@@ -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];