Re: [PATCH v13 06/10] usb: dwc3: qcom: Enable wakeup for applicable ports of multiport

From: Krishna Kurapati PSSNV
Date: Mon Oct 23 2023 - 13:27:37 EST




On 10/23/2023 9:17 PM, Johan Hovold wrote:
On Sat, Oct 07, 2023 at 09:18:02PM +0530, Krishna Kurapati wrote:
Currently wakeup is supported by only single port controllers. Read speed
of each port and accordingly enable IRQ's for those ports.

Signed-off-by: Krishna Kurapati <quic_kriskura@xxxxxxxxxxx>
---
drivers/usb/dwc3/dwc3-qcom.c | 65 +++++++++++++++++++-----------------
1 file changed, 35 insertions(+), 30 deletions(-)

diff --git a/drivers/usb/dwc3/dwc3-qcom.c b/drivers/usb/dwc3/dwc3-qcom.c
index 863892284146..651b9775a0c2 100644
--- a/drivers/usb/dwc3/dwc3-qcom.c
+++ b/drivers/usb/dwc3/dwc3-qcom.c
@@ -90,7 +90,7 @@ struct dwc3_qcom {
*/
int phy_irq[NUM_PHY_IRQ - 1][DWC3_MAX_PORTS];
int hs_phy_irq;
- enum usb_device_speed usb2_speed;
+ enum usb_device_speed usb2_speed[DWC3_MAX_PORTS];

This also belongs in a new port structure.

struct extcon_dev *edev;
struct extcon_dev *host_edev;
@@ -335,7 +335,8 @@ static bool dwc3_qcom_is_host(struct dwc3_qcom *qcom)
return dwc->xhci;
}
-static enum usb_device_speed dwc3_qcom_read_usb2_speed(struct dwc3_qcom *qcom)
+static enum usb_device_speed dwc3_qcom_read_usb2_speed(struct dwc3_qcom *qcom,
+ int port_index)

No need for line break (since it's a function definition).

{
struct dwc3 *dwc = platform_get_drvdata(qcom->dwc3);
struct usb_device *udev;
@@ -348,12 +349,10 @@ static enum usb_device_speed dwc3_qcom_read_usb2_speed(struct dwc3_qcom *qcom)
/*
* It is possible to query the speed of all children of
- * USB2.0 root hub via usb_hub_for_each_child(). DWC3 code
- * currently supports only 1 port per controller. So
- * this is sufficient.
+ * USB2.0 root hub via usb_hub_for_each_child().

This comment no longer makes sense with your current implementation.

Can you help elaborate on your comment ? Do you mean that this API doesn't get speed on all ports, but this has to be called in a loop to get all the port speeds ? In that sense, I agree, I can change the comments here.

But perhaps this should be done using usb_hub_for_each_child() instead
as that may be more efficient. Then you use this function to read out
the speed for all the ports in go (and store it in the port structures I
mentioned). Please determine which alternative is best.

Either ways is fine. We would have qcom->num_ports to determine how many speeds we can read.

*/
#ifdef CONFIG_USB
- udev = usb_hub_find_child(hcd->self.root_hub, 1);
+ udev = usb_hub_find_child(hcd->self.root_hub, port_index + 1);
#else
udev = NULL;
#endif
@@ -386,23 +385,29 @@ static void dwc3_qcom_disable_wakeup_irq(int irq)
static void dwc3_qcom_disable_interrupts(struct dwc3_qcom *qcom)
{
+ int i;
+
dwc3_qcom_disable_wakeup_irq(qcom->hs_phy_irq);
- if (qcom->usb2_speed == USB_SPEED_LOW) {
- dwc3_qcom_disable_wakeup_irq(qcom->phy_irq[DM_HS_PHY_IRQ_INDEX][0]);
- } else if ((qcom->usb2_speed == USB_SPEED_HIGH) ||
- (qcom->usb2_speed == USB_SPEED_FULL)) {
- dwc3_qcom_disable_wakeup_irq(qcom->phy_irq[DP_HS_PHY_IRQ_INDEX][0]);
- } else {
- dwc3_qcom_disable_wakeup_irq(qcom->phy_irq[DP_HS_PHY_IRQ_INDEX][0]);
- dwc3_qcom_disable_wakeup_irq(qcom->phy_irq[DM_HS_PHY_IRQ_INDEX][0]);
- }
+ for (i = 0; i < qcom->num_ports; i++) {
+ if (qcom->usb2_speed[i] == USB_SPEED_LOW) {
+ dwc3_qcom_disable_wakeup_irq(qcom->phy_irq[DM_HS_PHY_IRQ_INDEX][i]);
+ } else if ((qcom->usb2_speed[i] == USB_SPEED_HIGH) ||
+ (qcom->usb2_speed[i] == USB_SPEED_FULL)) {
+ dwc3_qcom_disable_wakeup_irq(qcom->phy_irq[DP_HS_PHY_IRQ_INDEX][i]);
+ } else {
+ dwc3_qcom_disable_wakeup_irq(qcom->phy_irq[DP_HS_PHY_IRQ_INDEX][i]);
+ dwc3_qcom_disable_wakeup_irq(qcom->phy_irq[DM_HS_PHY_IRQ_INDEX][i]);
+ }
- dwc3_qcom_disable_wakeup_irq(qcom->phy_irq[SS_PHY_IRQ_INDEX][0]);
+ dwc3_qcom_disable_wakeup_irq(qcom->phy_irq[SS_PHY_IRQ_INDEX][i]);
+ }
}

The above is hardly readable, partly because of the 2d array that I
think you should drop, and partly because you add the port loop here
instead of in the caller.

A lot of these functions should become port operation where you either
pass in a port structure directly or possibly a port index as I've
mentioned before.

With your suggestion, yes, this can be refactored to be readable.


[ I realise that the confusion around hs_phy_irq may be partly to blame
for this but since that one is also a per-port interrupt, that's no
longer an issue. ]

I don't want to add support for this right away [1]. I would like to keep hs_phy_irq outside the loop for now.

static int dwc3_qcom_suspend(struct dwc3_qcom *qcom, bool wakeup)
@@ -454,10 +461,8 @@ static int dwc3_qcom_suspend(struct dwc3_qcom *qcom, bool wakeup)
* The role is stable during suspend as role switching is done from a
* freezable workqueue.
*/
- if (dwc3_qcom_is_host(qcom) && wakeup) {
- qcom->usb2_speed = dwc3_qcom_read_usb2_speed(qcom);

So just let this function update the usb2 speed for all ports unless
there are reasons not to.

Either way is fine by me as mentioned above. Will udapte code accordingly.


+ if (dwc3_qcom_is_host(qcom) && wakeup)
dwc3_qcom_enable_interrupts(qcom);

And then iterate over the ports and enable the interrupts here as you
did above for the pwr_evnt_irqs.

- }
qcom->is_suspended = true;
[1]: https://lore.kernel.org/all/fb5e5e1d-520c-4cbc-adde-f30e853421a1@xxxxxxxxxxx/

Regards,
Krishna,