Hi,
> From: Roger Quadros
> Sent: Thursday, April 07, 2016 8:45 PM
>
> Hi,
>
> On 07/04/16 11:52, Yoshihiro Shimoda wrote:
> > Hi,
> >
> >> From: Roger Quadros
> >> Sent: Tuesday, April 05, 2016 11:05 PM
< snip >
> > diff --git a/drivers/usb/common/usb-otg.c b/drivers/usb/common/usb-otg.c
> > index 41e762a..4d7f043 100644
> > --- a/drivers/usb/common/usb-otg.c
> > +++ b/drivers/usb/common/usb-otg.c
> > @@ -825,11 +825,16 @@ int usb_otg_register_hcd(struct usb_hcd *hcd, unsigned int irqnum,
> > if (otg->primary_hcd.hcd) {
> > /* probably a shared HCD ? */
> > if (usb_otg_hcd_is_primary_hcd(hcd)) {
> > + if (hcd->driver->flags & HCD_USB11) {
> > + dev_info(otg_dev, "this assumes usb 1.1 hc is as shared_hcd\n");
> > + goto check_shared_hcd;
> > + }
> > dev_err(otg_dev, "otg: primary host already registered\n");
> > goto err;
> > }
> >
> > if (hcd->shared_hcd == otg->primary_hcd.hcd) {
> > +check_shared_hcd:
> > if (otg->shared_hcd.hcd) {
> > dev_err(otg_dev, "otg: shared host already registered\n");
> > goto err;
> >
> > What do you think this local hack?
>
> Is it guaranteed that EHCI hcd registers before OHCI hcd?
Thank you for the comment. No, it is not guaranteed.
> If not we need to improve the code still.
> We will also need to remove the constraint that primary_hcd must be registered
> first in usb_otg_register_hcd(). I think that constraint is no longer
> needed anyways.
I got it.
So, I made a patch to avoid the constraint using an additional property "otg-hcds".
The patch is in this end of email. What do you think about the patch?
> If EHCI & OHCI HCDs register before OTG driver then things will break unless
> we fix usb_otg_hcd_wait_add(). We need to add this HCD_USB11 check there to
> populate wait->shared_hcd.
I see. In my environment, since EHCI & OHCI HCDs need phy driver and phy driver
will calls usb_otg_register(), the order is right. In other words,
EHCI & OHCI HCDs never register before OTG driver because even if EHCI driver
is probed first, the driver will be deferred (EHCI driver needs the phy driver).
> > I also wonder if array of hcd may be good for both xHCI and EHCI/OHCI.
> > For example of xHCI:
> > - otg->hcds[0] = primary_hcd
> > - otg->hcds[1] = shared_hcd
> >
> > For example of EHCI/OHCI:
> > - otg->hcds[0] = primary_hcd of EHCI
> > - otg->hcds[1] = primary_hcd of OHCI
>
> The bigger problem is that how do we know in the OHCI/EHCI case that we need to wait
> for both of them before starting the OTG FSM?
> Some systems might use just OHCI or just EHCI.
>
> There is no guarantee that OTG driver registers before the HCDs so this piece
> of information must come from the HCD itself. i.e. whether it needs a companion or not.
I understood these problems. I wonder if my patch can resolve these problems.
Best regards,
Yoshihiro Shimoda
---
diff --git a/Documentation/devicetree/bindings/usb/generic.txt b/Documentation/devicetree/bindings/usb/generic.txt
index f6866c1..518b9eb 100644
--- a/Documentation/devicetree/bindings/usb/generic.txt
+++ b/Documentation/devicetree/bindings/usb/generic.txt
@@ -27,6 +27,12 @@ Optional properties:
- otg-controller: phandle to otg controller. Host or gadget controllers can
contain this property to link it to a particular OTG
controller.
+ - otg-hcds: phandle to host controller(s). An OTG controller can contain this
+ property. The first one is as "primary", and (optional) the second
+ one is as "shared".
+ - For example for xHCI: otg-hcds = <&xhci>, <&xhci>;
+ - For example for EHCI/OHCI: otg-hcds = <&ehci>, <&ohci>;
+ - For example for just EHCI: otg-hcds = <&ehci>;
This is an attribute to a USB controller such as:
diff --git a/arch/arm64/boot/dts/renesas/r8a7795.dtsi b/arch/arm64/boot/dts/renesas/r8a7795.dtsi
index 741d9d2..9dcf76ac 100644
--- a/arch/arm64/boot/dts/renesas/r8a7795.dtsi
+++ b/arch/arm64/boot/dts/renesas/r8a7795.dtsi
@@ -1253,6 +1253,7 @@
compatible = "renesas,usb2-phy-r8a7795";
reg = <0 0xee080200 0 0x700>;
interrupts = <GIC_SPI 108 IRQ_TYPE_LEVEL_HIGH>;
+ otg-hcds = <&ehci0>, <&ohci0>;
clocks = <&cpg CPG_MOD 703>;
power-domains = <&sysc R8A7795_PD_ALWAYS_ON>;
#phy-cells = <0>;
diff --git a/drivers/usb/common/usb-otg.c b/drivers/usb/common/usb-otg.c
index 41e762a..9a78482 100644
--- a/drivers/usb/common/usb-otg.c
+++ b/drivers/usb/common/usb-otg.c
@@ -258,7 +258,8 @@ static void usb_otg_flush_wait(struct device *otg_dev)
dev_dbg(otg_dev, "otg: registering pending host/gadget\n");
gadget = &wait->gcd;
- if (gadget)
+ /* I'm not sure but gadget->gadget is possible to be NULL */
+ if (gadget && gadget->gadget)
usb_otg_register_gadget(gadget->gadget, gadget->ops);
host = &wait->primary_hcd;
@@ -567,6 +568,8 @@ struct usb_otg *usb_otg_register(struct device *dev,
{
struct usb_otg *otg;
struct otg_wait_data *wait;
+ struct device_node *np;
+ struct platform_device *pdev;
int ret = 0;
if (!dev || !config || !config->fsm_ops)
@@ -616,6 +619,40 @@ struct usb_otg *usb_otg_register(struct device *dev,
list_add_tail(&otg->list, &otg_list);
mutex_unlock(&otg_list_mutex);
+ /* Get primary hcd device (mandatory) */
+ np = of_parse_phandle(dev->of_node, "otg-hcds", 0);
+ if (!np) {
+ dev_err(dev, "no otg-hcds\n");
+ ret = -EINVAL;
+ goto err_dt;
+ }
+ pdev = of_find_device_by_node(np);
+ of_node_put(np);
+ if (!pdev) {
+ dev_err(dev, "coulnd't get primary hcd device\n");
+ ret = -ENODEV;
+ goto err_dt;
+ }
+ otg->primary_dev = &pdev->dev;
+
+ /* Get shared hcd device (optional) */
+ np = of_parse_phandle(dev->of_node, "otg-hcds", 1);
+ if (np) {
+ pdev = of_find_device_by_node(np);
+ of_node_put(np);
+ if (!pdev) {
+ dev_err(dev, "coulnd't get shared hcd device\n");
+ ret = -ENODEV;
+ goto err_dt;
+ }
+ otg->shared_dev = &pdev->dev;
+ } else {
+ dev_dbg(dev, "no shared hcd\n");
+ }
+
+ if (otg->primary_dev != otg->shared_dev)
+ otg->flags |= OTG_FLAG_SHARED_IS_2ND_PRIMARY;
+
/* were we in wait list? */
mutex_lock(&wait_list_mutex);
wait = usb_otg_get_wait(dev);
@@ -627,6 +664,8 @@ struct usb_otg *usb_otg_register(struct device *dev,
return otg;
+err_dt:
+ destroy_workqueue(otg->wq);
err_wq:
kfree(otg);
unlock:
@@ -822,50 +861,42 @@ int usb_otg_register_hcd(struct usb_hcd *hcd, unsigned int irqnum,
/* HCD will be started by OTG fsm when needed */
mutex_lock(&otg->fsm.lock);
- if (otg->primary_hcd.hcd) {
- /* probably a shared HCD ? */
- if (usb_otg_hcd_is_primary_hcd(hcd)) {
- dev_err(otg_dev, "otg: primary host already registered\n");
- goto err;
+ if (!otg->primary_hcd.hcd) {
+ dev_info(hcd_dev, "%s: primary %s, now %s\n", __func__,
+ dev_name(otg->primary_dev),
+ dev_name(hcd->self.controller));
+ if (otg->primary_dev == hcd->self.controller) {
+ otg->primary_hcd.hcd = hcd;
+ otg->primary_hcd.irqnum = irqnum;
+ otg->primary_hcd.irqflags = irqflags;
+ otg->primary_hcd.ops = ops;
+ otg->hcd_ops = ops;
+ dev_info(otg_dev, "otg: primary host %s registered\n",
+ dev_name(hcd->self.controller));
}
+ }
- if (hcd->shared_hcd == otg->primary_hcd.hcd) {
- if (otg->shared_hcd.hcd) {
- dev_err(otg_dev, "otg: shared host already registered\n");
- goto err;
- }
-
+ if (!otg->shared_hcd.hcd && (!usb_otg_hcd_is_primary_hcd(hcd) ||
+ otg->flags & OTG_FLAG_SHARED_IS_2ND_PRIMARY)) {
+ dev_info(hcd_dev, "%s: shared %s, now %s\n", __func__,
+ dev_name(otg->shared_dev),
+ dev_name(hcd->self.controller));
+ if (otg->shared_dev == hcd->self.controller) {
otg->shared_hcd.hcd = hcd;
otg->shared_hcd.irqnum = irqnum;
otg->shared_hcd.irqflags = irqflags;
otg->shared_hcd.ops = ops;
dev_info(otg_dev, "otg: shared host %s registered\n",
dev_name(hcd->self.controller));
- } else {
- dev_err(otg_dev, "otg: invalid shared host %s\n",
- dev_name(hcd->self.controller));
- goto err;
- }
- } else {
- if (!usb_otg_hcd_is_primary_hcd(hcd)) {
- dev_err(otg_dev, "otg: primary host must be registered first\n");
- goto err;
}
-
- otg->primary_hcd.hcd = hcd;
- otg->primary_hcd.irqnum = irqnum;
- otg->primary_hcd.irqflags = irqflags;
- otg->primary_hcd.ops = ops;
- otg->hcd_ops = ops;
- dev_info(otg_dev, "otg: primary host %s registered\n",
- dev_name(hcd->self.controller));
}
/*
* we're ready only if we have shared HCD
* or we don't need shared HCD.
*/
- if (otg->shared_hcd.hcd || !otg->primary_hcd.hcd->shared_hcd) {
+ if (otg->primary_hcd.hcd && (!otg->shared_dev ||
+ (otg->shared_dev && otg->shared_hcd.hcd))) {
otg->host = hcd_to_bus(hcd);
/* FIXME: set bus->otg_port if this is true OTG port with HNP */
@@ -878,10 +909,6 @@ int usb_otg_register_hcd(struct usb_hcd *hcd, unsigned int irqnum,
mutex_unlock(&otg->fsm.lock);
return 0;
-
-err:
- mutex_unlock(&otg->fsm.lock);
- return -EINVAL;
}
EXPORT_SYMBOL_GPL(usb_otg_register_hcd);
diff --git a/include/linux/usb/otg.h b/include/linux/usb/otg.h
index b094352..ed08865 100644
--- a/include/linux/usb/otg.h
+++ b/include/linux/usb/otg.h
@@ -51,6 +51,8 @@ struct otg_hcd {
* @fsm: otg finite state machine
* @hcd_ops: host controller interface
* ------- internal use only -------
+ * @primary_dev: primary host device for matching
+ * @shared_dev: (optional) shared or other primary host device for matching
* @primary_hcd: primary host state and interface
* @shared_hcd: shared host state and interface
* @gadget_ops: gadget controller interface
@@ -75,6 +77,8 @@ struct usb_otg {
struct otg_hcd_ops *hcd_ops;
/* internal use only */
+ struct device *primary_dev;
+ struct device *shared_dev;
struct otg_hcd primary_hcd;
struct otg_hcd shared_hcd;
struct otg_gadget_ops *gadget_ops;
@@ -84,6 +88,7 @@ struct usb_otg {
u32 flags;
#define OTG_FLAG_GADGET_RUNNING (1 << 0)
#define OTG_FLAG_HOST_RUNNING (1 << 1)
+#define OTG_FLAG_SHARED_IS_2ND_PRIMARY (1 << 2)
/* use otg->fsm.lock for serializing access */
/*------------- deprecated interface -----------------------------*/
--
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