Jonathan Cameron wrote on 2011-02-05: > On 12/19/10 20:33, Jonathan Cameron wrote: >> This set is an update of the proof of concept I wrote a while back. >> This time around I've simply used a byte stream buffer rather than >> variable record sizes. The first patch pushes some of the exiting >> buffer code down into the ring_sw implementation to make it simpler to >> provide other implementations. >> >> What you gain by picking kfifo: >> * Clean fast code for the underlying buffer. >> >> What you loose: >> * Events - userspace has to 'know' how often to read the buffer >> so as to not loose data. >> Obvious difference is it is a fifo rather than a ring buffer. >> >> This buffer should also lend itself to a simple implementation of a >> store_n function which should be useful for devices with a hardware >> ring which we then want to feed into a software one. > > If anyone has time to take a look at this, it would be great to get > some feedback. If not I propose merging it anyway soon. > There is still work to be done to get this to an optimal state, but > right now it works so might as well make it available. A while ago I applied and tested this patch. I looked and seemed to work fine. I have to admit I didn't do extensive testing with it. -Michael > I fear my sw_ring implementation is one of the main blockers to moving > IIO out of staging so would like to show how easy it is to use > alternatives. On that note we should probably have some documentation > to provide a clear explanation of when to pick one buffer over another. > > The 'What option should a distro use?' question Greg raised the other > day will here be controlled by driver writers setting a suitable > default buffer choice if they implement multiple options. >> >> Jonathan Cameron (5): >> staging:iio:buffering move the copy to user on rip down into >> implementations >> staging:iio:kfifo buffer implementation >> staging:iio:lis3l02dq allow buffer implementation selection >> staging:iio: update example to handle case with no ring events >> staging:iio: buffer example - add lots more runtime parameters >> drivers/staging/iio/Documentation/generic_buffer.c | 63 +++++-- >> drivers/staging/iio/Kconfig | 6 + >> drivers/staging/iio/Makefile | 1 + >> drivers/staging/iio/accel/Kconfig | 23 +++- >> drivers/staging/iio/accel/lis3l02dq.h | 10 + >> drivers/staging/iio/accel/lis3l02dq_ring.c | 9 +- >> drivers/staging/iio/industrialio-ring.c | 23 +-- >> drivers/staging/iio/kfifo_buf.c | 196 >> ++++++++++++++++++++ drivers/staging/iio/kfifo_buf.h >> | 56 ++++++ drivers/staging/iio/ring_generic.h | >> 2 +- drivers/staging/iio/ring_sw.c | 29 ++- >> drivers/staging/iio/ring_sw.h | 4 +- 12 files >> changed, 363 insertions(+), 59 deletions(-) create mode >> 100644 drivers/staging/iio/kfifo_buf.c create mode 100644 >> drivers/staging/iio/kfifo_buf.h >> > Greetings, Michael -- Analog Devices GmbH Wilhelm-Wagenfeld-Str. 6 80807 Muenchen Sitz der Gesellschaft: Muenchen; Registergericht: Muenchen HRB 40368; Geschaeftsfuehrer:Dr.Carsten Suckrow, Thomas Wessel, William A. Martin, Margaret Seif -- To unsubscribe from this list: send the line "unsubscribe linux-iio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
