usb: dwc3: core: Skip setting event buffers for host only controllers

On some SoC's like SA8295P where the tertiary controller is host-only
capable, GEVTADDRHI/LO, GEVTSIZ, GEVTCOUNT registers are not accessible.
Trying to access them leads to a crash.

For DRD/Peripheral supported controllers, event buffer setup is done
again in gadget_pullup. Skip setup or cleanup of event buffers if
controller is host-only capable.

Suggested-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Krishna Kurapati <quic_kriskura@quicinc.com>
Acked-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
Reviewed-by: Johan Hovold <johan+linaro@kernel.org>
Reviewed-by: Bjorn Andersson <andersson@kernel.org>
Tested-by: Johan Hovold <johan+linaro@kernel.org>
Link: https://lore.kernel.org/r/20240420044901.884098-4-quic_kriskura@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index 38fcf530332f4b01fd07e511f39283e6e510d66c..733b1e24af54dc7520cb0a530e9bd3b4d4c6483e 100644 (file)
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -486,6 +486,13 @@ static void dwc3_free_event_buffers(struct dwc3 *dwc)
 static int dwc3_alloc_event_buffers(struct dwc3 *dwc, unsigned int length)
 {
        struct dwc3_event_buffer *evt;
+       unsigned int hw_mode;
+
+       hw_mode = DWC3_GHWPARAMS0_MODE(dwc->hwparams.hwparams0);
+       if (hw_mode == DWC3_GHWPARAMS0_MODE_HOST) {
+               dwc->ev_buf = NULL;
+               return 0;
+       }
 
        evt = dwc3_alloc_one_event_buffer(dwc, length);
        if (IS_ERR(evt)) {
@@ -507,6 +514,9 @@ int dwc3_event_buffers_setup(struct dwc3 *dwc)
 {
        struct dwc3_event_buffer        *evt;
 
+       if (!dwc->ev_buf)
+               return 0;
+
        evt = dwc->ev_buf;
        evt->lpos = 0;
        dwc3_writel(dwc->regs, DWC3_GEVNTADRLO(0),
@@ -524,6 +534,9 @@ void dwc3_event_buffers_cleanup(struct dwc3 *dwc)
 {
        struct dwc3_event_buffer        *evt;
 
+       if (!dwc->ev_buf)
+               return;
+
        evt = dwc->ev_buf;
 
        evt->lpos = 0;