Re: [PATCH] pxa_camera: Documentation of the FSM
Guennadi Liakhovetski writes: > > Cool, nice:-) One question though: shouldn't the "capture list empty" > transition start from "Videobuf released" state? Absolutely. Nice catch. I just cross-checked my hand-made schema, and you're right. > Or maybe you want to reorginise the "Videobuf released" and "Frame completed" > states a bit to separate cases > - capture list empty > - capture list not empty > - DMA still running - hot-linking success > - DMA stopped - restart Well, granted that the transition "capture list empty" was badly put, this is not needed anymore, is it ? Cheers. -- Robert >From 8f33b15891c8fe8ee317a8d0d7293d05fda3c6e6 Mon Sep 17 00:00:00 2001 From: Robert Jarzmik Date: Mon, 13 Apr 2009 18:52:56 +0200 Subject: [PATCH] pxa_camera: Documentation of the FSM After DMA redesign, the pxa_camera dynamic behaviour should be documented so that future contributors understand how it works, and improve it. Signed-off-by: Robert Jarzmik --- Documentation/video4linux/pxa_camera.txt | 49 ++ 1 files changed, 49 insertions(+), 0 deletions(-) diff --git a/Documentation/video4linux/pxa_camera.txt b/Documentation/video4linux/pxa_camera.txt index b1137f9..4f6d0ca 100644 --- a/Documentation/video4linux/pxa_camera.txt +++ b/Documentation/video4linux/pxa_camera.txt @@ -26,6 +26,55 @@ Global video workflow Once the last buffer is filled in, the QCI interface stops. + c) Capture global finite state machine schema + + ++ +---+ ++ + | DQ | | Q | | DQ | + |v | v |v ++---+ ++ +| STOP| | Wait for capture start | ++---+ Q ++ ++-> | QCI: stop | --> | QCI: run | <+ +| | DMA: stop | | DMA: stop | | +| +---+ +-> ++ | +|/| | +| / +---+ ++ | | +|capture list empty/ | Q | | DQ | | QCI Irq EOF | +| / | v |v v | +| ++ +--+ | +| | DMA hotlink missed | |Capture running | | +| ++ +--+ | +| | QCI: run | +-> | QCI: run | <-+ | +| | DMA: stop |/| DMA: run | | | +| ++ / +--+ | Other | +| ^ /DMA still| | channels | +| | capture list / running | DMA Irq End | not | +| | not empty / | | finished | +| | /v | yet | +| +--+ +--+ | | +| | Videobuf released | | Channel completed | | | +| +--+ +--+ | | ++-- | QCI: run | | QCI: run | --+ | +| DMA: run | | DMA: run | | ++--+ +--+ | + ^ / | | + | no overrun /| overrun | + |/ v | +++ / +--+ | +| Frame completed |/| Frame overran| | +++ <-+ +--+ restart frame | +| QCI: run | | QCI: stop| --+ +| DMA: run | | DMA: stop| +++ +--+ + +Legend: - each box is a FSM state +- each arrow is the condition to transition to another state +- an arrow with a comment is a mandatory transition (no condition) +- arrow "Q" means : a buffer was enqueued +- arrow "DQ" means : a buffer was dequeued +- "QCI: stop" means the QCI interface is not enabled +- "DMA: stop" means all 3 DMA channels are stop
Re: [PATCH] pxa_camera: Documentation of the FSM
On Mon, 13 Apr 2009, Robert Jarzmik wrote: > After DMA redesign, the pxa_camera dynamic behaviour should > be documented so that future contributors understand how it > works, and improve it. > > Signed-off-by: Robert Jarzmik > --- > Documentation/video4linux/pxa_camera.txt | 49 > ++ > 1 files changed, 49 insertions(+), 0 deletions(-) > > diff --git a/Documentation/video4linux/pxa_camera.txt > b/Documentation/video4linux/pxa_camera.txt > index b1137f9..b595e94 100644 > --- a/Documentation/video4linux/pxa_camera.txt > +++ b/Documentation/video4linux/pxa_camera.txt > @@ -26,6 +26,55 @@ Global video workflow > > Once the last buffer is filled in, the QCI interface stops. > > + c) Capture global finite state machine schema > + > + ++ +---+ ++ > + | DQ | | Q | | DQ | > + |v | v |v > ++---+ ++ > +| STOP| | Wait for capture start | > ++---+ Q ++ > ++-> | QCI: stop | --> | QCI: run | > <+ > +| | DMA: stop | | DMA: stop | > | > +| +---+ +-> ++ > | > +|/| > | > +| / +---+ ++ | > | > +|capture list empty/ | Q | | DQ | | QCI Irq EOF > | > +| / | v |v v > | > +| ++ +--+ > | > +| | DMA hotlink missed | |Capture running | > | > +| ++ +--+ > | > +| | QCI: run | +-> | QCI: run | <-+ > | > +| | DMA: stop |/| DMA: run | | > | > +| ++ / +--+ | Other > | > +| ^ /DMA still| | channels > | > +| | capture list / running | DMA Irq End | not > | > +| | not empty / | | finished > | > +| | /v | yet > | > +| +--+ +--+ | > | > +| | Videobuf released | | Channel completed | | > | > +| +--+ +--+ | > | > +| | QCI: run | | QCI: run | --+ > | > +| | DMA: run | | DMA: run | > | > +| +--+ +--+ > | > +| ^ / | > | > +| | no overrun /| overrun > | > +| |/ v > | > +| ++ / +--+ > | > +| | Frame completed |/| Frame overran| > | > +| ++ <-+ +--+ restart > frame | > ++-- | QCI: run | | QCI: stop| > --+ > +| DMA: run | | DMA: stop| > +++ +--+ > + > +Legend: - each box is a FSM state > +- each arrow is the condition to transition to another state > +- an arrow with a comment is a mandatory transition (no > condition) > +- arrow "Q" means : a buffer was enqueued > +- arrow "DQ" means : a buffer was dequeued > +- "QCI: stop" means the QCI interface is not enabled > +- "DMA: stop" means all 3 DMA channels are stopped > +- "DMA: run" means at least 1 DMA channel is still running > > DMA usage > - Cool, nice:-) One question though: shouldn't the "capture list empty" transition start from "Videobuf released" state? Or maybe you want to reorginise the "Videobuf released" and "Frame completed" states a bit to separate cases - capture list empty - capture list not empty - DMA still running - hot-linking success - DMA stopped - restart Thanks Guennadi --- Guennadi Liakhovetski, Ph.D. Freelance Open-Source Software Developer -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majord...@vger.kernel.or
[PATCH] pxa_camera: Documentation of the FSM
After DMA redesign, the pxa_camera dynamic behaviour should be documented so that future contributors understand how it works, and improve it. Signed-off-by: Robert Jarzmik --- Documentation/video4linux/pxa_camera.txt | 49 ++ 1 files changed, 49 insertions(+), 0 deletions(-) diff --git a/Documentation/video4linux/pxa_camera.txt b/Documentation/video4linux/pxa_camera.txt index b1137f9..b595e94 100644 --- a/Documentation/video4linux/pxa_camera.txt +++ b/Documentation/video4linux/pxa_camera.txt @@ -26,6 +26,55 @@ Global video workflow Once the last buffer is filled in, the QCI interface stops. + c) Capture global finite state machine schema + + ++ +---+ ++ + | DQ | | Q | | DQ | + |v | v |v ++---+ ++ +| STOP| | Wait for capture start | ++---+ Q ++ ++-> | QCI: stop | --> | QCI: run | <+ +| | DMA: stop | | DMA: stop | | +| +---+ +-> ++ | +|/| | +| / +---+ ++ | | +|capture list empty/ | Q | | DQ | | QCI Irq EOF | +| / | v |v v | +| ++ +--+ | +| | DMA hotlink missed | |Capture running | | +| ++ +--+ | +| | QCI: run | +-> | QCI: run | <-+ | +| | DMA: stop |/| DMA: run | | | +| ++ / +--+ | Other | +| ^ /DMA still| | channels | +| | capture list / running | DMA Irq End | not | +| | not empty / | | finished | +| | /v | yet | +| +--+ +--+ | | +| | Videobuf released | | Channel completed | | | +| +--+ +--+ | | +| | QCI: run | | QCI: run | --+ | +| | DMA: run | | DMA: run | | +| +--+ +--+ | +| ^ / | | +| | no overrun /| overrun | +| |/ v | +| ++ / +--+ | +| | Frame completed |/| Frame overran| | +| ++ <-+ +--+ restart frame | ++-- | QCI: run | | QCI: stop| --+ +| DMA: run | | DMA: stop| +++ +--+ + +Legend: - each box is a FSM state +- each arrow is the condition to transition to another state +- an arrow with a comment is a mandatory transition (no condition) +- arrow "Q" means : a buffer was enqueued +- arrow "DQ" means : a buffer was dequeued +- "QCI: stop" means the QCI interface is not enabled +- "DMA: stop" means all 3 DMA channels are stopped +- "DMA: run" means at least 1 DMA channel is still running DMA usage - -- 1.6.2.1 -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
