On 6/24/2023 3:57 AM, Thinh Nguyen wrote:
On Wed, Jun 21, 2023, Krishna Kurapati wrote:
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@xxxxxxxxxx>
Signed-off-by: Krishna Kurapati <quic_kriskura@xxxxxxxxxxx>
---
drivers/usb/dwc3/core.c | 11 +++++++++++
1 file changed, 11 insertions(+)
diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index 32ec05fc242b..e1ebae54454f 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -486,6 +486,11 @@ 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)
+ return 0;
This is a little awkward. Returning 0 here indicates that this function
was successful, and the event buffers were allocated based on the
function name. Do this check outside of dwc3_alloc_one_event_buffer()
and specifically set dwc->ev_buf = NULL if that's the case.
Hi Thinh,
Apologies, I didn't understand the comment properly.
I thought we were supposed to return 0 here if we fulfill the goal of
this function (allocate if we are drd/gadget and don't allocate if we
are host mode only).
If we return a non zero error here, probe would fail as this call
will be done only for host only controllers during probe and nowhere else.
Are you suggesting we move this check to dwc3_alloc_one_event_buffer
call ?
Regards,
Krishna,
evt = dwc3_alloc_one_event_buffer(dwc, length);
if (IS_ERR(evt)) {
@@ -507,6 +512,9 @@ 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 +532,9 @@ 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;
--
2.40.0
