> On 07 Jun 2017, at 09:53, Marek Vasut <ma...@denx.de> wrote: > > On 06/07/2017 09:49 AM, Dr. Philipp Tomsich wrote: >>> On 07 Jun 2017, at 08:28, Marek Vasut <ma...@denx.de >>> <mailto:ma...@denx.de>> wrote: >>> >>> On 06/06/2017 05:11 PM, Dr. Philipp Tomsich wrote: >>>> >>>>> On 06 Jun 2017, at 16:35, Marek Vasut <ma...@denx.de >>>>> <mailto:ma...@denx.de>> wrote: >>>>> >>>>> On 06/06/2017 03:42 PM, Philipp Tomsich wrote: >>>>>> 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.toms...@theobroma-systems.com >>>>>> <mailto:philipp.toms...@theobroma-systems.com>> >>>>>> >>>>>> --- >>>>>> >>>>>> 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"); >>>>> >>>>> You print an error, but still continue with the function ? That'll >>>>> probably lead to a crash, you should rather abort. In fact, I suspect >>>>> you can use bounce-buffer to assure the dma buffer is in 32bit space. >>>> >>>> This tries to stay close to the current behaviour (we have no >>>> hardware to test this, >>>> but I wanted to get it out of the way as it caused buildman-failures) >>>> and to provide >>>> diagnostics for whoever first encounters an issue here. >>>> >>>> Note that I would only expect a DMA error, if someone really hit this >>>> issue ... >>> >>> So this patch is just some hypothetical fix ? What triggered creation of >>> this patch ? >> >> Running buildman (w/ a GCC 6.3 configured as aarch-unknown-elf) against >> unrelated >> patch-series (for a Rockchip device that has a different USB controller) >> fails due to the >> warnings raised from this. Just casting those warnings away (without >> having an >> “assertion-like” diagnostic printed) doesn’t sound like the best plan >> either, though. >> >> Details of the buildman-failure are in the above commit-message. > > Ah, hm. In that case, you should really implement the bounce buffer here > I think. Letting the transfer continue will lead to really weird > failures and/or memory corruption.
Alright. I’ll put it to (the back of) my queue and resubmit. Someone (with hardware) will need to test, once it’s submitted. Cheers, Philipp. _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de https://lists.denx.de/listinfo/u-boot
