[PATCH] usb: gadget: cdns3: Fix missing cache operations for non-zero Endpoints

[Siddharth Vadapalli]

Transfer initiation and completion for the non-zero Endpoints are
handled by cdns3_ep_run_transfer() and cdns3_transfer_completed()
respectively.

Failing to flush the cache associated with the TRB Pool within
cdns3_ep_run_transfer() results in the transfers never being initiated.
Similarly, failing to invalidate the cache associated with the TRB pool
within cdns3_transfer_completed() results in the transfers never being
completed.

Fix this.

Fixes: 7e91f6ccdc84 ("usb: Add Cadence USB3 host and gadget driver")
Signed-off-by: Siddharth Vadapalli <s-vadapalli at ti.com>
---

Hello,

This patch is based on commit
56b47b8b6a Merge tag 'u-boot-stm32-20240926' of https://source.denx.de/u-boot/custodians/u-boot-stm
of the master branch of U-Boot.

This patch has been validated on AM642-EVM in the context of Fastboot.
Fastboot is non-functional without this patch. EP1 is configured in
Bulk Mode for Fastboot and is non-responsive. This patch addresses the
issue, thereby enabling Fastboot.

Regards,
Siddharth.

 drivers/usb/cdns3/gadget.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/drivers/usb/cdns3/gadget.c b/drivers/usb/cdns3/gadget.c
index 32b2c41206..ac7e469469 100644
--- a/drivers/usb/cdns3/gadget.c
+++ b/drivers/usb/cdns3/gadget.c
@@ -965,6 +965,12 @@ int cdns3_ep_run_transfer(struct cdns3_endpoint *priv_ep,
 	if (priv_dev->dev_ver <= DEV_VER_V2)
 		cdns3_wa1_tray_restore_cycle_bit(priv_dev, priv_ep);
 
+	/* Flush TRBs */
+	flush_dcache_range((unsigned long)priv_ep->trb_pool,
+			   (unsigned long)priv_ep->trb_pool +
+			   ROUND(sizeof(struct cdns3_trb) * priv_ep->num_trbs,
+				 CONFIG_SYS_CACHELINE_SIZE));
+
 	trace_cdns3_prepare_trb(priv_ep, priv_req->trb);
 
 	/*
@@ -1153,6 +1159,13 @@ static void cdns3_transfer_completed(struct cdns3_device *priv_dev,
 				priv_ep->endpoint.desc->bEndpointAddress);
 #endif
 
+		/* Invalidate TRBs */
+		invalidate_dcache_range((unsigned long)priv_ep->trb_pool,
+					(unsigned long)priv_ep->trb_pool +
+					ROUND(sizeof(struct cdns3_trb) *
+					      priv_ep->num_trbs,
+					      CONFIG_SYS_CACHELINE_SIZE));
+
 		if (!cdns3_request_handled(priv_ep, priv_req))
 			goto prepare_next_td;
 
-- 
2.40.1