[PATCH v20 3/9] usb: dwc3: core: Skip setting event buffers for host only controllers

Krishna Kurapati
2024-04-08T13:30:30Z

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>
---
drivers/usb/dwc3/core.c | 13 +++++++++++++
1 file changed, 13 insertions(+)

diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index ddab30531f8a..1a3d8a9beea8 100644
--- 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;
--
2.34.1