[PATCH v3] usb: xhci: allow imod-interval to be configurable
Mathias Nyman
mathias.nyman at linux.intel.com
Mon Dec 4 00:57:02 PST 2017
On 03.12.2017 05:22, Chunfeng Yun wrote:
> On Fri, 2017-12-01 at 10:44 -0500, Adam Wallis wrote:
>> 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", 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.
>>
>> Signed-off-by: Adam Wallis <awallis at codeaurora.org>
>> ---
>> changes from v2:
>> * Added PCI default value [Mathias]
>> * Removed xhci-mtk.h from xhci-plat.c [Chunfeng Yun]
>> * Removed MTK quirk from xhci-plat and moved logic to xhci-mtk [Chunfeng]
>> * Updated bindings Documentation to use proper units [Rob Herring]
>> * Added imod-interval description and example to MTK binding documentation
>> changes from v1:
>> * Removed device_property_read_u32() per suggestion from greg k-h
>> * Used ER_IRQ_INTERVAL_MASK in place of (u16) cast
>>
>> 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 | 4 ++++
>> drivers/usb/host/xhci.c | 7 ++-----
>> 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..45bbf18 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: Default interval is 5000ns
> I think, as Rob suggested before, recommend to have a unit suffix
> appended to the property name.
> s/imod-interval/imod-interval-ns
>
>>
>> Example:
>> usb30: usb at 11270000 {
>> @@ -66,6 +67,7 @@ usb30: usb at 11270000 {
>> usb3-lpm-capable;
>> mediatek,syscon-wakeup = <&pericfg>;
>> mediatek,wakeup-src = <1>;
>> + imod-interval = <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 ae6e484..89b68f1 100644
>> --- a/Documentation/devicetree/bindings/usb/usb-xhci.txt
>> +++ b/Documentation/devicetree/bindings/usb/usb-xhci.txt
>> @@ -29,6 +29,7 @@ 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: Default interval is 40000ns
>>
>> Example:
>> usb at f0931000 {
>> diff --git a/drivers/usb/host/xhci-mtk.c b/drivers/usb/host/xhci-mtk.c
>> index b62a1d2..278ea3b 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 modulation 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", &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..efbe57b 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 modulation 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..b78be87 100644
>> --- a/drivers/usb/host/xhci-plat.c
>> +++ b/drivers/usb/host/xhci-plat.c
>> @@ -269,6 +269,10 @@ 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 modulation value in nanoseconds. */
>> + xhci->imod_interval = 40000;
>> + device_property_read_u32(sysdev, "imod-interval", &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 2424d30..0b7755b 100644
>> --- a/drivers/usb/host/xhci.c
>> +++ b/drivers/usb/host/xhci.c
>> @@ -586,11 +586,8 @@ int xhci_run(struct usb_hcd *hcd)
>> "// Set the interrupt modulation register");
Just noticed the driver has all the time incorrectly used the word "modulation" instead
of "moderation".
If you do the bindings change that Chunfeng pointed out above could you also change
the "modulation" to "moderation" in this patch.
Don't worry about changing the old ones. There's a cleanup patch on its way that
will remove most of them anyway.
Otherwise the xhci parts look good to me.
-Mathias
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