Hi, On 31/10/2019 10:55, Felipe Balbi wrote:
Hi, Roger Quadros <rogerq@xxxxxx> 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@xxxxxx> Acked-by: Peter Chen <peter.chen@xxxxxxx> --- 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
