On Mon, Jan 07, 2019 at 11:45:24PM -0500, Paul Elder wrote: > Hi Bin, > > On Mon, Jan 07, 2019 at 01:11:57PM -0600, Bin Liu wrote: > > Hi Paul, > > > > Sorry for the delay on reviewing it. > > Thanks for the review. > > > For the subject, can you please use > > > > usb: musb: gadget: fix short isoc packets with inventra dma > > ack > > > On Tue, Oct 09, 2018 at 02:32:20AM -0400, Paul Elder wrote: > > > Handling short packets (length < max packet size) in the Inventra DMA > > > engine in the MUSB driver causes the MUSB DMA controller to hang. An > > > example of a problem that is caused by this problem is when streaming > > > video out of a UVC gadget, only the first video frame is transferred. > > > > > > For short packets (mode-0 or mode-1 DMA), MUSB_TXCSR_TXPKTRDY must be > > > set manually by the driver. This was previously done in musb_g_tx > > > (musb_gadget.c), but incorrectly (all csr flags were cleared, and only > > > MUSB_TXCSR_MODE and MUSB_TXCSR_TXPKTRDY). Fixing that problem allows > > > some requests to be transferred correctly, but multiple requests were > > > often put together in one USB packet, and caused problems if the packet > > > size was not a multiple of 4. > > > > > > Instead, MUSB_TXCSR_TXPKTRDY is set in dma_controller_irq (musbhsdma.c), > > > just like host mode transfers, then musb_g_tx forces the packet to be > > > flushed, by setting MUSB_TXCSR_FLUSHFIFO. This should be reworded, since we don't set MUSB_TXCSR_FLUSHFIFO in the code. > > > > > > This topic was originally tackled by Nicolas Boichat [0] [1] and is discussed > > > > this line is longer than 75 chars. > > ack > > > > further at [2] as part of his GSoC project [3]. > > > > > > [0] https://groups.google.com/forum/?hl=en#!topic/beagleboard-gsoc/k8Azwfp75CU > > > [1] https://gitorious.org/beagleboard-usbsniffer/beagleboard-usbsniffer-kernel/commit/b0be3b6cc195ba732189b04f1d43ec843c3e54c9?p=beagleboard-usbsniffer:beagleboard-usbsniffer-kernel.git;a=patch;h=b0be3b6cc195ba732189b04f1d43ec843c3e54c9 > > > [2] http://beagleboard-usbsniffer.blogspot.com/2010/07/musb-isochronous-transfers-fixed.html > > > [3] http://elinux.org/BeagleBoard/GSoC/USBSniffer > > > > > > I have forward-ported this patch from 2.6.34 to 4.19-rc1. > > > > this line is irrelevant to the commit message, please move it down to > > under '---'. > > ack > > > > > > > Signed-off-by: Paul Elder <paul.elder@xxxxxxxxxxxxxxxx> > > > --- > > > drivers/usb/musb/musb_gadget.c | 21 ++++++++++++++------- > > > drivers/usb/musb/musbhsdma.c | 21 +++++++++++---------- > > > 2 files changed, 25 insertions(+), 17 deletions(-) > > > > > > diff --git a/drivers/usb/musb/musb_gadget.c b/drivers/usb/musb/musb_gadget.c > > > index eae8b1b1b45b..d3f33f449445 100644 > > > --- a/drivers/usb/musb/musb_gadget.c > > > +++ b/drivers/usb/musb/musb_gadget.c > > > @@ -479,11 +479,16 @@ void musb_g_tx(struct musb *musb, u8 epnum) > > > && (request->actual == request->length)) > > > short_packet = true; > > > > > > - if ((musb_dma_inventra(musb) || musb_dma_ux500(musb)) && > > > - (is_dma && (!dma->desired_mode || > > > - (request->actual & > > > - (musb_ep->packet_sz - 1))))) > > > - short_packet = true; > > > + if (is_dma && (musb_dma_inventra(musb) || musb_dma_ux500(musb))) { > > > > more than 80 chars. > > > > > + if (!dma->desired_mode || > > > > I understand you forward-port Nicolas' patch, but do you have a specific > > readon to re-write this 'if' condition? I'd like to see minimum code > > change in bug fixes, > > > > > + request->actual % musb_ep->packet_sz) { > > > > but I like this version though, easier to read. > > > > > + musb_dbg(musb, "%s Flushing (FIFO) EP : KPB\n", > > > > what is 'KPB'? the message could be more meaningful? > > > > > + musb_ep->end_point.name); > > > + musb_writew(epio, MUSB_TXCSR, > > > + csr | MUSB_TXCSR_FLUSHFIFO); > > > > What if without this line? The short packet doesn't send out? setting > > TXSCR_TXPKTRDY in the dma driver is not sufficient? TXSCR_FLUSHFIFO is > > only used for aborting cases. > > I just tested this and you are right, it does work without this line. > Since this is the only significant line in this very complex if block, > I'll just remove this entire block too. > > > > + return; > > > + } > > > + } > > > > > > if (short_packet) { > > > /* > > > @@ -493,8 +498,10 @@ void musb_g_tx(struct musb *musb, u8 epnum) > > > if (csr & MUSB_TXCSR_TXPKTRDY) > > > return; > > > > > > - musb_writew(epio, MUSB_TXCSR, MUSB_TXCSR_MODE > > > - | MUSB_TXCSR_TXPKTRDY); > > > + musb_dbg(musb, "sending zero pkt (zero=%d, length=%d, actual=%d, dma->desired_mode=%d)\n", actually this is not a 'zero' packet, it is a short packet. > > > + request->zero, request->length, request->actual, > > > > more than 80 chars. > > The format string or the parameters? Never mind. I meant the parameters, but it is only 1 char longer, just leave it like this. > > > > > > + dma->desired_mode); > > > + musb_writew(epio, MUSB_TXCSR, csr | MUSB_TXCSR_TXPKTRDY); > > > > more than 80 chars. > > It's only by 1 character. Should I still put the last argument on a new > line? same here, never mind my comment. > > > > > > request->zero = 0; > > > } > > > > > > diff --git a/drivers/usb/musb/musbhsdma.c b/drivers/usb/musb/musbhsdma.c > > > index a688f7f87829..e514d4700a6b 100644 > > > --- a/drivers/usb/musb/musbhsdma.c > > > +++ b/drivers/usb/musb/musbhsdma.c > > > @@ -346,12 +346,10 @@ static irqreturn_t dma_controller_irq(int irq, void *private_data) > > > channel->status = MUSB_DMA_STATUS_FREE; > > > > > > /* completed */ > > > - if ((devctl & MUSB_DEVCTL_HM) > > > - && (musb_channel->transmit) > > > - && ((channel->desired_mode == 0) > > > - || (channel->actual_len & > > > - (musb_channel->max_packet_sz - 1))) > > > - ) { > > > + if (musb_channel->transmit && > > > + (!channel->desired_mode || > > > + (channel->actual_len % > > > + musb_channel->max_packet_sz))) { > > > > improper indentation. > > ack. You don't think this is more readable than if everything was lined > up? The original version has 4-chars indentation, I think it is clearer. > > > > u8 epnum = musb_channel->epnum; > > > int offset = musb->io.ep_offset(epnum, > > > MUSB_TXCSR); > > > @@ -363,11 +361,14 @@ static irqreturn_t dma_controller_irq(int irq, void *private_data) > > > */ > > > musb_ep_select(mbase, epnum); > > > txcsr = musb_readw(mbase, offset); > > > - txcsr &= ~(MUSB_TXCSR_DMAENAB > > > + if (channel->desired_mode == 1) { > > > + txcsr &= ~(MUSB_TXCSR_DMAENAB > > > | MUSB_TXCSR_AUTOSET); > > > - musb_writew(mbase, offset, txcsr); > > > - /* Send out the packet */ > > > - txcsr &= ~MUSB_TXCSR_DMAMODE; > > > + musb_writew(mbase, offset, txcsr); > > > > more than 80 chars. > > This is also only by 2 characters; do you still want just the last > argument on a new line? never mind my comment. Regards, -Bin.
