| Message ID | 20190109071009.27625-1-paul.elder@ideasonboard.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [v2] usb: gadget: musb: fix short isoc packets with inventra dma | expand |
Hi Paul, On Wed, Jan 09, 2019 at 02:10:09AM -0500, 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 were set). 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, set MUSB_TXCSR_TXPKTRDY > in dma_controller_irq (musbhsdma.c), just like host mode transfers. > > This topic was originally tackled by Nicolas Boichat [0] [1] and is > discussed 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 > > Signed-off-by: Paul Elder <paul.elder@ideasonboard.com> > --- > Changes in v2: > > - no more flushing FIFO > - greatly simplified short packet if guard in musb_g_tx, and removed > unnecessary variables > - minor indentation and wording changes > > drivers/usb/musb/musb_gadget.c | 19 +++++-------------- > drivers/usb/musb/musbhsdma.c | 21 +++++++++++---------- > 2 files changed, 16 insertions(+), 24 deletions(-) > > diff --git a/drivers/usb/musb/musb_gadget.c b/drivers/usb/musb/musb_gadget.c > index eae8b1b1b45b..496643f54faa 100644 > --- a/drivers/usb/musb/musb_gadget.c > +++ b/drivers/usb/musb/musb_gadget.c > @@ -452,13 +452,10 @@ void musb_g_tx(struct musb *musb, u8 epnum) > } > > if (request) { > - u8 is_dma = 0; > - bool short_packet = false; > > trace_musb_req_tx(req); > > if (dma && (csr & MUSB_TXCSR_DMAENAB)) { > - is_dma = 1; > csr |= MUSB_TXCSR_P_WZC_BITS; > csr &= ~(MUSB_TXCSR_DMAENAB | MUSB_TXCSR_P_UNDERRUN | > MUSB_TXCSR_TXPKTRDY | MUSB_TXCSR_AUTOSET); > @@ -476,16 +473,8 @@ void musb_g_tx(struct musb *musb, u8 epnum) > */ > if ((request->zero && request->length) > && (request->length % musb_ep->packet_sz == 0) > - && (request->actual == request->length)) > - short_packet = true; > + && (request->actual == request->length)) { > > - 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 (short_packet) { > /* > * On DMA completion, FIFO may not be > * available yet... > @@ -493,8 +482,10 @@ 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 short pkt (zero=%d, length=%d, actual=%d, dma->desired_mode=%d)\n", > + request->zero, request->length, request->actual, > + dma->desired_mode); > + musb_writew(epio, MUSB_TXCSR, csr | MUSB_TXCSR_TXPKTRDY); Sorry I didn't catch this in the last review, but this change seems not required, isn't it? In the first version of the patch, the code is 'returned' in the 'if (musb_dma_inventra())' branch above, doesn't reach here. Regards, -Bin.
Hi Bin, On Wed, Jan 09, 2019 at 09:02:15AM -0600, Bin Liu wrote: > Hi Paul, > > On Wed, Jan 09, 2019 at 02:10:09AM -0500, 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 were set). 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, set MUSB_TXCSR_TXPKTRDY > > in dma_controller_irq (musbhsdma.c), just like host mode transfers. > > > > This topic was originally tackled by Nicolas Boichat [0] [1] and is > > discussed 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 > > > > Signed-off-by: Paul Elder <paul.elder@ideasonboard.com> > > --- > > Changes in v2: > > > > - no more flushing FIFO > > - greatly simplified short packet if guard in musb_g_tx, and removed > > unnecessary variables > > - minor indentation and wording changes > > > > drivers/usb/musb/musb_gadget.c | 19 +++++-------------- > > drivers/usb/musb/musbhsdma.c | 21 +++++++++++---------- > > 2 files changed, 16 insertions(+), 24 deletions(-) > > > > diff --git a/drivers/usb/musb/musb_gadget.c b/drivers/usb/musb/musb_gadget.c > > index eae8b1b1b45b..496643f54faa 100644 > > --- a/drivers/usb/musb/musb_gadget.c > > +++ b/drivers/usb/musb/musb_gadget.c > > @@ -452,13 +452,10 @@ void musb_g_tx(struct musb *musb, u8 epnum) > > } > > > > if (request) { > > - u8 is_dma = 0; > > - bool short_packet = false; > > > > trace_musb_req_tx(req); > > > > if (dma && (csr & MUSB_TXCSR_DMAENAB)) { > > - is_dma = 1; > > csr |= MUSB_TXCSR_P_WZC_BITS; > > csr &= ~(MUSB_TXCSR_DMAENAB | MUSB_TXCSR_P_UNDERRUN | > > MUSB_TXCSR_TXPKTRDY | MUSB_TXCSR_AUTOSET); > > @@ -476,16 +473,8 @@ void musb_g_tx(struct musb *musb, u8 epnum) > > */ > > if ((request->zero && request->length) > > && (request->length % musb_ep->packet_sz == 0) > > - && (request->actual == request->length)) > > - short_packet = true; > > + && (request->actual == request->length)) { > > > > - 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 (short_packet) { > > /* > > * On DMA completion, FIFO may not be > > * available yet... > > @@ -493,8 +482,10 @@ 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 short pkt (zero=%d, length=%d, actual=%d, dma->desired_mode=%d)\n", > > + request->zero, request->length, request->actual, > > + dma->desired_mode); > > + musb_writew(epio, MUSB_TXCSR, csr | MUSB_TXCSR_TXPKTRDY); > > Sorry I didn't catch this in the last review, but this change seems not > required, isn't it? In the first version of the patch, the code is > 'returned' in the 'if (musb_dma_inventra())' branch above, doesn't reach > here. Do you mean change compared to the last version of the patch, or this last chunk of the diff? I guess I did also remove the return when I removed the 'if (musb_dma_inventra())' block that had the FLUSHFIFIO, but when I tested it it still worked. In fact, I reverted this last diff chunk and it still worked. Paul
Hi Paul, On Fri, Jan 11, 2019 at 12:31:59AM -0500, Paul Elder wrote: > Hi Bin, > > On Wed, Jan 09, 2019 at 09:02:15AM -0600, Bin Liu wrote: > > Hi Paul, > > > > On Wed, Jan 09, 2019 at 02:10:09AM -0500, 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 were set). 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, set MUSB_TXCSR_TXPKTRDY > > > in dma_controller_irq (musbhsdma.c), just like host mode transfers. > > > > > > This topic was originally tackled by Nicolas Boichat [0] [1] and is > > > discussed 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 > > > > > > Signed-off-by: Paul Elder <paul.elder@ideasonboard.com> > > > --- > > > Changes in v2: > > > > > > - no more flushing FIFO > > > - greatly simplified short packet if guard in musb_g_tx, and removed > > > unnecessary variables > > > - minor indentation and wording changes > > > > > > drivers/usb/musb/musb_gadget.c | 19 +++++-------------- > > > drivers/usb/musb/musbhsdma.c | 21 +++++++++++---------- > > > 2 files changed, 16 insertions(+), 24 deletions(-) > > > > > > diff --git a/drivers/usb/musb/musb_gadget.c b/drivers/usb/musb/musb_gadget.c > > > index eae8b1b1b45b..496643f54faa 100644 > > > --- a/drivers/usb/musb/musb_gadget.c > > > +++ b/drivers/usb/musb/musb_gadget.c > > > @@ -452,13 +452,10 @@ void musb_g_tx(struct musb *musb, u8 epnum) > > > } > > > > > > if (request) { > > > - u8 is_dma = 0; > > > - bool short_packet = false; > > > > > > trace_musb_req_tx(req); > > > > > > if (dma && (csr & MUSB_TXCSR_DMAENAB)) { > > > - is_dma = 1; > > > csr |= MUSB_TXCSR_P_WZC_BITS; > > > csr &= ~(MUSB_TXCSR_DMAENAB | MUSB_TXCSR_P_UNDERRUN | > > > MUSB_TXCSR_TXPKTRDY | MUSB_TXCSR_AUTOSET); > > > @@ -476,16 +473,8 @@ void musb_g_tx(struct musb *musb, u8 epnum) > > > */ > > > if ((request->zero && request->length) > > > && (request->length % musb_ep->packet_sz == 0) > > > - && (request->actual == request->length)) > > > - short_packet = true; > > > + && (request->actual == request->length)) { > > > > > > - 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 (short_packet) { > > > /* > > > * On DMA completion, FIFO may not be > > > * available yet... > > > @@ -493,8 +482,10 @@ 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 short pkt (zero=%d, length=%d, actual=%d, dma->desired_mode=%d)\n", > > > + request->zero, request->length, request->actual, > > > + dma->desired_mode); > > > + musb_writew(epio, MUSB_TXCSR, csr | MUSB_TXCSR_TXPKTRDY); > > > > Sorry I didn't catch this in the last review, but this change seems not > > required, isn't it? In the first version of the patch, the code is > > 'returned' in the 'if (musb_dma_inventra())' branch above, doesn't reach > > here. > > Do you mean change compared to the last version of the patch, or this > last chunk of the diff? I meant that the chunk above seems not related to this webcam short packet test case, so am wondering if this change is not neccessary - musb_writew(epio, MUSB_TXCSR, MUSB_TXCSR_MODE - | MUSB_TXCSR_TXPKTRDY); + musb_writew(epio, MUSB_TXCSR, csr | MUSB_TXCSR_TXPKTRDY); > > I guess I did also remove the return when I removed the 'if > (musb_dma_inventra())' block that had the FLUSHFIFIO, but when I tested > it it still worked. In fact, I reverted this last diff chunk and it > still worked. so the last chunk is not related, we don't have to touch it. Regards, -Bin.
diff --git a/drivers/usb/musb/musb_gadget.c b/drivers/usb/musb/musb_gadget.c index eae8b1b1b45b..496643f54faa 100644 --- a/drivers/usb/musb/musb_gadget.c +++ b/drivers/usb/musb/musb_gadget.c @@ -452,13 +452,10 @@ void musb_g_tx(struct musb *musb, u8 epnum) } if (request) { - u8 is_dma = 0; - bool short_packet = false; trace_musb_req_tx(req); if (dma && (csr & MUSB_TXCSR_DMAENAB)) { - is_dma = 1; csr |= MUSB_TXCSR_P_WZC_BITS; csr &= ~(MUSB_TXCSR_DMAENAB | MUSB_TXCSR_P_UNDERRUN | MUSB_TXCSR_TXPKTRDY | MUSB_TXCSR_AUTOSET); @@ -476,16 +473,8 @@ void musb_g_tx(struct musb *musb, u8 epnum) */ if ((request->zero && request->length) && (request->length % musb_ep->packet_sz == 0) - && (request->actual == request->length)) - short_packet = true; + && (request->actual == request->length)) { - 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 (short_packet) { /* * On DMA completion, FIFO may not be * available yet... @@ -493,8 +482,10 @@ 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 short pkt (zero=%d, length=%d, actual=%d, dma->desired_mode=%d)\n", + request->zero, request->length, request->actual, + dma->desired_mode); + musb_writew(epio, MUSB_TXCSR, csr | MUSB_TXCSR_TXPKTRDY); request->zero = 0; } diff --git a/drivers/usb/musb/musbhsdma.c b/drivers/usb/musb/musbhsdma.c index a688f7f87829..5fc6825745f2 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))) { 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); + /* Send out the packet */ + txcsr &= ~MUSB_TXCSR_DMAMODE; + txcsr |= MUSB_TXCSR_DMAENAB; + } txcsr |= MUSB_TXCSR_TXPKTRDY; musb_writew(mbase, offset, txcsr); }
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 were set). 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, set MUSB_TXCSR_TXPKTRDY in dma_controller_irq (musbhsdma.c), just like host mode transfers. This topic was originally tackled by Nicolas Boichat [0] [1] and is discussed 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 Signed-off-by: Paul Elder <paul.elder@ideasonboard.com> --- Changes in v2: - no more flushing FIFO - greatly simplified short packet if guard in musb_g_tx, and removed unnecessary variables - minor indentation and wording changes drivers/usb/musb/musb_gadget.c | 19 +++++-------------- drivers/usb/musb/musbhsdma.c | 21 +++++++++++---------- 2 files changed, 16 insertions(+), 24 deletions(-)