On 5/17/2023 5:41 AM, Thinh Nguyen wrote:
On Sun, May 14, 2023, Krishna Kurapati wrote:
Currently for dwc3_usb31 controller, if maximum_speed is limited to
super-speed in DT, then device mode is limited to SS, but host mode
still works in SSP.
The documentation for max-speed property is as follows:
"Tells USB controllers we want to work up to a certain speed.
Incase this isn't passed via DT, USB controllers should default to
their maximum HW capability."
It doesn't specify that the property is only for device mode.
There are cases where we need to limit the host's maximum speed to
SuperSpeed only. Use this property for host mode to contrain host's
speed to SuperSpeed.
Signed-off-by: Krishna Kurapati <quic_kriskura@xxxxxxxxxxx>
---
Link to v1: https://urldefense.com/v3/__https://lore.kernel.org/all/20230512170107.18821-1-quic_kriskura@xxxxxxxxxxx/__;!!A4F2R9G_pg!dCg_3WK2oNXNb6d0a_VuyjkeeZJTU1aY4dik6g35XB7mtG7EJeR1uPMfxFja49OfXp7Yhsg1yqjnylCYYEg7YCAhqfAZ0Q$
Discussion regarding the same at:
https://urldefense.com/v3/__https://lore.kernel.org/all/e465c69c-3a9d-cbdb-d44e-96b99cfa1a92@xxxxxxxxxxx/__;!!A4F2R9G_pg!dCg_3WK2oNXNb6d0a_VuyjkeeZJTU1aY4dik6g35XB7mtG7EJeR1uPMfxFja49OfXp7Yhsg1yqjnylCYYEg7YCDRLUrJWg$
drivers/usb/dwc3/core.c | 8 ++++++++
drivers/usb/dwc3/core.h | 5 +++++
2 files changed, 13 insertions(+)
diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index 278cd1c33841..33bc72595e74 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -1262,6 +1262,14 @@ static int dwc3_core_init(struct dwc3 *dwc)
}
}
+ if ((hw_mode != DWC3_GHWPARAMS0_MODE_GADGET) &&
+ (DWC3_IP_IS(DWC31)) &&
+ (dwc->maximum_speed == USB_SPEED_SUPER)) {
+ reg = dwc3_readl(dwc->regs, DWC3_LLUCTL);
+ reg |= DWC3_LLUCTL_FORCE_GEN1;
+ dwc3_writel(dwc->regs, DWC3_LLUCTL, reg);
+ }
+
Perhaps this should be done for every usb3 port rather than just the
port_0. This patch can go after your multi-port series is added to
Greg's branch where you can check for number of usb3 ports.
Thanks,
Thinh
Hi Thinh,
Seems like multiport would take little more time and I need this
patch to be ported to ACK for fixing customer issue. Would it be
possible to take this patch as is ? Once multiport is done, I will send
another patch to include the changes for mutliport as well.
Regards,
Krishna,
