Messages in this thread | ![/](/images/icornerl.gif) | | Subject | Re: [PATCH v2] usb: cdns3: gadget: Fix g_audio use case when connected to Super-Speed host | From | Roger Quadros <> | Date | Thu, 31 Oct 2019 12:35:28 +0200 |
| |
Hi,
On 31/10/2019 10:55, Felipe Balbi wrote: > > Hi, > > Roger Quadros <rogerq@ti.com> writes: > >> Take into account gadget driver's speed limit when programming >> controller speed. >> >> Fixes: commit 7733f6c32e36 ("usb: cdns3: Add Cadence USB3 DRD Driver") >> Signed-off-by: Roger Quadros <rogerq@ti.com> >> Acked-by: Peter Chen <peter.chen@nxp.com> >> --- >> >> Changelog: >> v2 >> - Add Fixes line >> >> drivers/usb/cdns3/gadget.c | 31 ++++++++++++++++++++++++++----- >> 1 file changed, 26 insertions(+), 5 deletions(-) >> >> diff --git a/drivers/usb/cdns3/gadget.c b/drivers/usb/cdns3/gadget.c >> index 40dad4e8d0dc..1c724c20d468 100644 >> --- a/drivers/usb/cdns3/gadget.c >> +++ b/drivers/usb/cdns3/gadget.c >> @@ -2338,9 +2338,35 @@ static int cdns3_gadget_udc_start(struct usb_gadget *gadget, >> { >> struct cdns3_device *priv_dev = gadget_to_cdns3_device(gadget); >> unsigned long flags; >> + enum usb_device_speed max_speed = driver->max_speed; >> >> spin_lock_irqsave(&priv_dev->lock, flags); >> priv_dev->gadget_driver = driver; >> + >> + /* limit speed if necessary */ >> + max_speed = min(driver->max_speed, gadget->max_speed); >> + >> + switch (max_speed) { >> + case USB_SPEED_FULL: >> + writel(USB_CONF_SFORCE_FS, &priv_dev->regs->usb_conf); >> + writel(USB_CONF_USB3DIS, &priv_dev->regs->usb_conf); >> + break; >> + case USB_SPEED_HIGH: >> + writel(USB_CONF_USB3DIS, &priv_dev->regs->usb_conf); >> + break; >> + case USB_SPEED_SUPER: >> + break; >> + default: >> + dev_err(priv_dev->dev, >> + "invalid maximum_speed parameter %d\n", >> + max_speed); >> + /* fall through */ >> + case USB_SPEED_UNKNOWN: >> + /* default to superspeed */ >> + max_speed = USB_SPEED_SUPER; >> + break; >> + } > > I had suggested some simplification for this case statement. >
oops, looks like Greg picked this already.
During more tests today I just observed that this patch causes the following regression.
Connect EVM to Super-Speed host Load g_audio. (this enumerates as HS which is fine) unload g_audio load g_zero (this enumerates at HS instead of SS).
This is because the speed limit that we set doesn't get cleared.
Now the bits are write only and there is a way to undo USB_CONF_SFORCE_FS by writing USB_CONF_CFORCE_FS, however there is no corresponding bit to clear USB_CONF_USB3DIS. Only way seems to be USB_CFG_SWRST which is a bit harsh IMO.
Pawel,
could you please confirm what is the best way to undo the high-speed limit?
-- cheers, -roger Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki. Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki
| ![\](/images/icornerr.gif) |