From: Bryan O'Donoghue <bryan.odonoghue@xxxxxxxxx>
The EHCI packet buffer in/out threshold is programmable for Intel Quark X1000 USB host
controller, and the default value is 0x20 dwords. The in/out threshold can be programmed
to 0x80 dwords, but only when isochronous/interrupt transactions are not initiated by
the USB host controller. This patch is to reconfigure the packet buffer in/out threshold
as maximal as possible, and it is 0x7F dwords since the USB host controller initiates
isochronous/interrupt transactions.
Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@xxxxxxxxx>
Signed-off-by: Alvin (Weike) Chen <alvin.chen@xxxxxxxxx>
---
changelog v2:
*Change the function name from 'usb_is_intel_qrk' to 'usb_is_intel_quark_x1000'.
*Move the functions 'usb_is_intel_quark_x1000' and 'usb_set_qrk_bulk_thresh'
from 'pci-quirks.c' to 'ehci-pci.c'.
*Remove unnecessary kernel message in the function of 'usb_set_qrk_bulk_thresh'.
*Remove 'unlikely' in the functions of 'ehci_pci_reinit'.
*Add white space after 'if'.
*Update the descriptions to make it more clearly.
*Add Micros to avoid magic number.
drivers/usb/host/ehci-pci.c | 45 +++++++++++++++++++++++++++++++++++++++++++
1 file changed, 45 insertions(+)
diff --git a/drivers/usb/host/ehci-pci.c b/drivers/usb/host/ehci-pci.c
index 3e86bf4..ca29f34 100644
--- a/drivers/usb/host/ehci-pci.c
+++ b/drivers/usb/host/ehci-pci.c
@@ -35,6 +35,47 @@ static const char hcd_name[] = "ehci-pci";
#define PCI_DEVICE_ID_INTEL_CE4100_USB 0x2e70
/*-------------------------------------------------------------------------*/
+#define PCI_DEVICE_ID_INTEL_QUARK_X1000_SOC 0x0939
+static inline bool usb_is_intel_quark_x1000(struct pci_dev *pdev)
+{
+ return pdev->vendor == PCI_VENDOR_ID_INTEL &&
+ pdev->device == PCI_DEVICE_ID_INTEL_QUARK_X1000_SOC;
+
+}
+
+/* Register offset of in/out threshold */
+#define EHCI_INSNREG01 0x84
+/* The maximal threshold is 0x80 Dword */
+#define EHCI_MAX_THRESHOLD 0X80
+/* Lower word is 'in' threshold, and higher word is 'out' threshold*/
+#define EHCI_INSNREG01_THRESH \
+ ((EHCI_MAX_THRESHOLD - 1)<<16 | (EHCI_MAX_THRESHOLD - 1))
+static void usb_set_qrk_bulk_thresh(struct pci_dev *pdev)
+{
+ void __iomem *base, *op_reg_base;
+ u8 cap_length;
+ u32 val;
+ u16 cmd;
+
+ if (!pci_resource_start(pdev, 0))
+ return;
+
+ if (pci_read_config_word(pdev, PCI_COMMAND, &cmd)
+ || !(cmd & PCI_COMMAND_MEMORY))
+ return;
+
+ base = pci_ioremap_bar(pdev, 0);
+ if (base == NULL)
+ return;
+
+ cap_length = readb(base);
+ op_reg_base = base + cap_length;
+
+ val = EHCI_INSNREG01_THRESH;
+ writel(val, op_reg_base + EHCI_INSNREG01);
+
+ iounmap(base);
+}
/* called after powerup, by probe or system-pm "wakeup" */
static int ehci_pci_reinit(struct ehci_hcd *ehci, struct pci_dev *pdev)
@@ -50,6 +91,10 @@ static int ehci_pci_reinit(struct ehci_hcd *ehci, struct pci_dev *pdev)
if (!retval)
ehci_dbg(ehci, "MWI active\n");
+ /* Reset the threshold limit */
+ if (usb_is_intel_quark_x1000(pdev))
+ usb_set_qrk_bulk_thresh(pdev);
+
return 0;
}
--
1.7.9.5
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