From: Adam Wallis <awallis@xxxxxxxxxxxxxx> The xHCI driver currently has the IMOD set to 160, which translates to an IMOD interval of 40,000ns (160 * 250)ns Commit 0cbd4b34cda9 ("xhci: mediatek: support MTK xHCI host controller") introduced a QUIRK for the MTK platform to adjust this interval to 20, which translates to an IMOD interval of 5,000ns (20 * 250)ns. This is due to the fact that the MTK controller IMOD interval is 8 times as much as defined in xHCI spec. Instead of adding more quirk bits for additional platforms, this patch introduces the ability for vendors to set the IMOD_INTERVAL as is optimal for their platform. By using device_property_read_u32() on "imod-interval-ns", the IMOD INTERVAL can be specified in nano seconds. If no interval is specified, the default of 40,000ns (IMOD=160) will be used. No bounds checking has been implemented due to the fact that a vendor may have violated the spec and would need to specify a value outside of the max 8,000 IRQs/second limit specified in the xHCI spec. Tested-by: Chunfeng Yun <chunfeng.yun@xxxxxxxxxxxx> Reviewed-by: Rob Herring <robh@xxxxxxxxxx> Signed-off-by: Adam Wallis <awallis@xxxxxxxxxxxxxx> Signed-off-by: Mathias Nyman <mathias.nyman@xxxxxxxxxxxxxxx> --- Documentation/devicetree/bindings/usb/mediatek,mtk-xhci.txt | 2 ++ Documentation/devicetree/bindings/usb/usb-xhci.txt | 1 + drivers/usb/host/xhci-mtk.c | 9 +++++++++ drivers/usb/host/xhci-pci.c | 3 +++ drivers/usb/host/xhci-plat.c | 5 +++++ drivers/usb/host/xhci.c | 6 +----- drivers/usb/host/xhci.h | 2 ++ 7 files changed, 23 insertions(+), 5 deletions(-) diff --git a/Documentation/devicetree/bindings/usb/mediatek,mtk-xhci.txt b/Documentation/devicetree/bindings/usb/mediatek,mtk-xhci.txt index 3059596..9ff5602 100644 --- a/Documentation/devicetree/bindings/usb/mediatek,mtk-xhci.txt +++ b/Documentation/devicetree/bindings/usb/mediatek,mtk-xhci.txt @@ -46,6 +46,7 @@ Optional properties: - pinctrl-names : a pinctrl state named "default" must be defined - pinctrl-0 : pin control group See: Documentation/devicetree/bindings/pinctrl/pinctrl-bindings.txt + - imod-interval-ns: default interrupt moderation interval is 5000ns Example: usb30: usb@11270000 { @@ -66,6 +67,7 @@ usb30: usb@11270000 { usb3-lpm-capable; mediatek,syscon-wakeup = <&pericfg>; mediatek,wakeup-src = <1>; + imod-interval-ns = <10000>; }; 2nd: dual-role mode with xHCI driver diff --git a/Documentation/devicetree/bindings/usb/usb-xhci.txt b/Documentation/devicetree/bindings/usb/usb-xhci.txt index a531071..e2ea59b 100644 --- a/Documentation/devicetree/bindings/usb/usb-xhci.txt +++ b/Documentation/devicetree/bindings/usb/usb-xhci.txt @@ -31,6 +31,7 @@ Optional properties: - usb2-lpm-disable: indicate if we don't want to enable USB2 HW LPM - usb3-lpm-capable: determines if platform is USB3 LPM capable - quirk-broken-port-ped: set if the controller has broken port disable mechanism + - imod-interval-ns: default interrupt moderation interval is 5000ns Example: usb@f0931000 { diff --git a/drivers/usb/host/xhci-mtk.c b/drivers/usb/host/xhci-mtk.c index b62a1d2..1cb2a8b 100644 --- a/drivers/usb/host/xhci-mtk.c +++ b/drivers/usb/host/xhci-mtk.c @@ -674,6 +674,15 @@ static int xhci_mtk_probe(struct platform_device *pdev) xhci = hcd_to_xhci(hcd); xhci->main_hcd = hcd; + + /* + * imod_interval is the interrupt moderation value in nanoseconds. + * The increment interval is 8 times as much as that defined in + * the xHCI spec on MTK's controller. + */ + xhci->imod_interval = 5000; + device_property_read_u32(dev, "imod-interval-ns", &xhci->imod_interval); + xhci->shared_hcd = usb_create_shared_hcd(driver, dev, dev_name(dev), hcd); if (!xhci->shared_hcd) { diff --git a/drivers/usb/host/xhci-pci.c b/drivers/usb/host/xhci-pci.c index 7ef1274..4bcddd4 100644 --- a/drivers/usb/host/xhci-pci.c +++ b/drivers/usb/host/xhci-pci.c @@ -234,6 +234,9 @@ static int xhci_pci_setup(struct usb_hcd *hcd) if (!xhci->sbrn) pci_read_config_byte(pdev, XHCI_SBRN_OFFSET, &xhci->sbrn); + /* imod_interval is the interrupt moderation value in nanoseconds. */ + xhci->imod_interval = 40000; + retval = xhci_gen_setup(hcd, xhci_pci_quirks); if (retval) return retval; diff --git a/drivers/usb/host/xhci-plat.c b/drivers/usb/host/xhci-plat.c index 09f164f..6f03830 100644 --- a/drivers/usb/host/xhci-plat.c +++ b/drivers/usb/host/xhci-plat.c @@ -269,6 +269,11 @@ static int xhci_plat_probe(struct platform_device *pdev) if (device_property_read_bool(&pdev->dev, "quirk-broken-port-ped")) xhci->quirks |= XHCI_BROKEN_PORT_PED; + /* imod_interval is the interrupt moderation value in nanoseconds. */ + xhci->imod_interval = 40000; + device_property_read_u32(sysdev, "imod-interval-ns", + &xhci->imod_interval); + hcd->usb_phy = devm_usb_get_phy_by_phandle(sysdev, "usb-phy", 0); if (IS_ERR(hcd->usb_phy)) { ret = PTR_ERR(hcd->usb_phy); diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c index 060e5b4..05104bd 100644 --- a/drivers/usb/host/xhci.c +++ b/drivers/usb/host/xhci.c @@ -583,11 +583,7 @@ int xhci_run(struct usb_hcd *hcd) "// Set the interrupt modulation register"); temp = readl(&xhci->ir_set->irq_control); temp &= ~ER_IRQ_INTERVAL_MASK; - /* - * the increment interval is 8 times as much as that defined - * in xHCI spec on MTK's controller - */ - temp |= (u32) ((xhci->quirks & XHCI_MTK_HOST) ? 20 : 160); + temp |= (xhci->imod_interval / 250) & ER_IRQ_INTERVAL_MASK; writel(temp, &xhci->ir_set->irq_control); /* Set the HCD state before we enable the irqs */ diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h index 7c87817..96099a2 100644 --- a/drivers/usb/host/xhci.h +++ b/drivers/usb/host/xhci.h @@ -1717,6 +1717,8 @@ struct xhci_hcd { u8 max_interrupters; u8 max_ports; u8 isoc_threshold; + /* imod_interval in ns (I * 250ns) */ + u32 imod_interval; int event_ring_max; /* 4KB min, 128MB max */ int page_size; -- 2.7.4 -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html