From: Christoph Hellwig <hch@infradead.org>
To: Felipe Balbi <balbi@kernel.org>
Cc: Christoph Hellwig <hch@infradead.org>,
John Stultz <john.stultz@linaro.org>,
"Yang, Fei" <fei.yang@intel.com>,
Andrzej Pietrasiewicz <andrzej.p@collabora.com>,
lkml <linux-kernel@vger.kernel.org>,
Felipe Balbi <felipe.balbi@linux.intel.com>,
Thinh Nguyen <thinhn@synopsys.com>,
Tejas Joglekar <tejas.joglekar@synopsys.com>,
Jack Pham <jackp@codeaurora.org>, Todd Kjos <tkjos@google.com>,
Greg KH <gregkh@linuxfoundation.org>,
Linux USB List <linux-usb@vger.kernel.org>,
stable <stable@vger.kernel.org>, Jens Axboe <axboe@kernel.dk>
Subject: Re: [RFC][PATCH 0/2] Avoiding DWC3 transfer stalls/hangs when using adb over f_fs
Date: Thu, 6 Feb 2020 10:41:34 -0800 [thread overview]
Message-ID: <20200206184134.GA11027@infradead.org> (raw)
In-Reply-To: <87ftfn602u.fsf@kernel.org>
On Thu, Feb 06, 2020 at 08:29:45PM +0200, Felipe Balbi wrote:
> > No, it shoudn't. dma_map_sg returns the number of mapped segments,
> > and the callers need to remember that.
>
> We _do_ remember that:
That helps :)
> that req->request.num_mapped_sgs is the returned value. So you're saying
> we should test for i == num_mapped_sgs, instead of using
> sg_is_last(). Is that it?
Yes.
> Fair enough. Just out of curiosity, then, when *should* we use
> sg_is_last()?
Outside of sg_next/sg_last it really shoud not be used at all as far
as I'm concerned.
next prev parent reply other threads:[~2020-02-06 18:41 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-22 22:26 [RFC][PATCH 0/2] Avoiding DWC3 transfer stalls/hangs when using adb over f_fs John Stultz
2020-01-22 22:26 ` [RFC][PATCH 1/2] usb: dwc3: gadget: Check for IOC/LST bit in both event->status and TRB->ctrl fields John Stultz
2020-01-23 7:24 ` Felipe Balbi
2020-01-23 18:54 ` Yang, Fei
2020-01-24 0:47 ` John Stultz
2020-01-24 7:45 ` Felipe Balbi
2020-01-24 22:10 ` John Stultz
2020-01-25 11:02 ` Felipe Balbi
2020-01-27 18:48 ` John Stultz
2020-01-22 22:26 ` [RFC][PATCH 2/2] usb: dwc3: gadget: Correct the logic for finding last SG entry John Stultz
2020-01-23 7:25 ` Felipe Balbi
2020-01-23 15:50 ` Anurag Kumar Vulisha
2020-01-23 7:18 ` [RFC][PATCH 0/2] Avoiding DWC3 transfer stalls/hangs when using adb over f_fs Felipe Balbi
2020-01-23 8:43 ` Andrzej Pietrasiewicz
2020-01-23 16:29 ` Yang, Fei
2020-01-23 17:31 ` Felipe Balbi
2020-01-23 17:37 ` Yang, Fei
2020-01-23 17:46 ` Felipe Balbi
2020-01-23 18:28 ` Yang, Fei
2020-02-05 21:03 ` John Stultz
2020-02-06 6:23 ` Felipe Balbi
2020-02-06 7:40 ` Christoph Hellwig
2020-02-06 18:29 ` Felipe Balbi
2020-02-06 18:41 ` Christoph Hellwig [this message]
2020-02-07 6:00 ` Felipe Balbi
2020-01-23 19:58 ` John Stultz
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