For LP64 build w/ GCC 6.3, the handling of the ep->dma_buf variable when (truncating and) writing into the controller's registers is unsafe and triggers the following compiler warning (thus failing by buildman tests): ../drivers/usb/gadget/dwc2_udc_otg_xfer_dma.c: In function 'setdma_rx': ../drivers/usb/gadget/dwc2_udc_otg_xfer_dma.c:116:9: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast] writel((unsigned int) ep->dma_buf, ®->out_endp[ep_num].doepdma); ^
This change fixes the warning and makes the code a bit more robust by doing the following: - we check whether ep->dma_buf can be safely truncated to 32 bits (i.e. whether dma_buf is the same value when masked to 32 bits) and emit an error message if that is not the case - we cast to a uintptr_t and let the writel macro truncate the uintptr_t (potentially a 64bit value) to 32bits
Signed-off-by: Philipp Tomsich philipp.tomsich@theobroma-systems.com
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Changes in v2: - (new patch) fix warnings and add some robustness for the truncation of ep->dma_buf in dwc2-otg for LP64 builds to fix a buildman failure for u-boot-rockchip/master@2b19b2f
drivers/usb/gadget/dwc2_udc_otg_xfer_dma.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/drivers/usb/gadget/dwc2_udc_otg_xfer_dma.c b/drivers/usb/gadget/dwc2_udc_otg_xfer_dma.c index 0d6d2fb..f5c926c 100644 --- a/drivers/usb/gadget/dwc2_udc_otg_xfer_dma.c +++ b/drivers/usb/gadget/dwc2_udc_otg_xfer_dma.c @@ -113,7 +113,11 @@ static int setdma_rx(struct dwc2_ep *ep, struct dwc2_request *req) invalidate_dcache_range((unsigned long) ep->dma_buf, (unsigned long) ep->dma_buf + ep->len);
- writel((unsigned int) ep->dma_buf, ®->out_endp[ep_num].doepdma); + /* ensure that ep->dma_buf fits into 32 bits */ + if (((uintptr_t)ep->dma_buf & 0xffffffff) != (uintptr_t)ep->dma_buf) + error("ep->dma_buf does not fit into a 32 bits"); + + writel((uintptr_t)ep->dma_buf, ®->out_endp[ep_num].doepdma); writel(DOEPT_SIZ_PKT_CNT(pktcnt) | DOEPT_SIZ_XFER_SIZE(length), ®->out_endp[ep_num].doeptsiz); writel(DEPCTL_EPENA|DEPCTL_CNAK|ctrl, ®->out_endp[ep_num].doepctl);