mmc: sdhci-pci-gli: Enlarge ASPM L1 entry delay of GL9763E

GL9763E enters ASPM L1 state after a very short idle in default,
even during a burst of request. So the R/W performance of GL9763E
is low with some platforms, which support ASPM mechanism, due to
entering ASPM L1 state very frequently in R/W process. Set the L1
entry delay bits in vendor-specific register to 0x3FF to enlarge
the idle period to 260us for improving the R/W performance
of GL9763E.
Signed-off-by: Renius Chen <reniuschengl@gmail.com>
Link: https://lore.kernel.org/r/20210115054736.27769-1-reniuschengl@gmail.comSigned-off-by: Ulf Hansson <ulf.hansson@linaro.org>

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

@@ -88,6 +88,10 @@
 #define PCIE_GLI_9763E_SCR	 0x8E0
 #define   GLI_9763E_SCR_AXI_REQ	   BIT(9)
 
+#define PCIE_GLI_9763E_CFG2      0x8A4
+#define   GLI_9763E_CFG2_L1DLY     GENMASK(28, 19)
+#define   GLI_9763E_CFG2_L1DLY_MAX 0x3FF
+
 #define PCIE_GLI_9763E_MMC_CTRL  0x960
 #define   GLI_9763E_HS400_SLOW     BIT(3)
 
@@ -792,6 +796,12 @@ static void gli_set_gl9763e(struct sdhci_pci_slot *slot)
 	value &= ~GLI_9763E_HS400_SLOW;
 	pci_write_config_dword(pdev, PCIE_GLI_9763E_MMC_CTRL, value);
 
+	pci_read_config_dword(pdev, PCIE_GLI_9763E_CFG2, &value);
+	value &= ~GLI_9763E_CFG2_L1DLY;
+	/* set ASPM L1 entry delay to 260us */
+	value |= FIELD_PREP(GLI_9763E_CFG2_L1DLY, GLI_9763E_CFG2_L1DLY_MAX);
+	pci_write_config_dword(pdev, PCIE_GLI_9763E_CFG2, 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);