Hi, Anurag Kumar Vulisha <anura...@xilinx.com> writes: > HI Felipe, > >>-----Original Message----- >>From: Felipe Balbi [mailto:ba...@kernel.org] >>Sent: Friday, December 07, 2018 11:42 AM >>To: Anurag Kumar Vulisha <anura...@xilinx.com>; Greg Kroah-Hartman >><gre...@linuxfoundation.org>; Shuah Khan <sh...@kernel.org>; Alan Stern >><st...@rowland.harvard.edu>; Johan Hovold <jo...@kernel.org>; Jaejoong Kim >><climbbb....@gmail.com>; Benjamin Herrenschmidt <b...@kernel.crashing.org>; >>Roger Quadros <rog...@ti.com>; Manu Gautam <mgau...@codeaurora.org>; >>martin.peter...@oracle.com; Bart Van Assche <bvanass...@acm.org>; Mike >>Christie <mchri...@redhat.com>; Matthew Wilcox <wi...@infradead.org>; Colin >>Ian >>King <colin.k...@canonical.com> >>Cc: linux-...@vger.kernel.org; linux-kernel@vger.kernel.org; >>v.anuragku...@gmail.com; Thinh Nguyen <thi...@synopsys.com>; Tejas Joglekar >><tejas.jogle...@synopsys.com>; Ajay Yugalkishore Pandey <apan...@xilinx.com> >>Subject: RE: [PATCH v7 09/10] usb: dwc3: Check for IOC/LST bit in both >>event->status >>and TRB->ctrl fields >> >> >>Hi, >> >>Anurag Kumar Vulisha <anura...@xilinx.com> writes: >>>>> @@ -2286,7 +2286,12 @@ static int >>>>dwc3_gadget_ep_reclaim_completed_trb(struct dwc3_ep *dep, >>>>> if (event->status & DEPEVT_STATUS_SHORT && !chain) >>>>> return 1; >>>>> >>>>> - if (event->status & (DEPEVT_STATUS_IOC | DEPEVT_STATUS_LST)) >>>>> + if ((event->status & DEPEVT_STATUS_IOC) && >>>>> + (trb->ctrl & DWC3_TRB_CTRL_IOC)) >>>>> + return 1; >>>> >>>>this shouldn't be necessary. According to databook, event->status >>>>contains the bits from the completed TRB. Which means that >>>>event->status & IOC will always be equal to trb->ctrl & IOC. >>>> >>> Thanks for reviewing this patch. Lets consider an example where a >>> request has num_sgs > 0 and each sg is mapped to a TRB and the last >>> TRB has the IOC bit set. Once the controller is done with the >>> transfer, it generates XferInProgress for the last TRB (since IOC bit >>> is set). As a part of trb reclaim process >>> dwc3_gadget_ep_reclaim_trb_sg() calls >>> dwc3_gadget_ep_reclaim_completed_trb() for req->num_sgs times. Since >>> the event already has the IOC bit set, the loop is exited from the >>> loop at the very first TRB and the remaining TRBs (mapped to the sglist) >>> are left >>unhandled. >>> To avoid this we modified the code to exit only if both TRB & event >>> has the IOC bit set. >> >>Seems like IOC case should just test for chain flag as well: >> > > Okay. Along with this logic the code for updating chain bit should also be > modified I guess.
not really > Since the IOC bit is also set when there are not enough TRBs available, the > code should be > modified to not set DWC3_TRB_CTRL_CHN bit when the IOC bit is set. I will > update below > changes along with your suggestions and resend the patches. no. Actually I don't think we're allowed to split a scatter/gather like that. I did that quite a while ago, but I don't think we're allowed to do so. What we should do, in that case, is not even queue that request until we have enough for all members of the scatter/gather. But that's a separate patch, anyway. -- balbi
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