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    SubjectRe: [PATCH] [0/6] kfifo fixes/improvements
    On Thu, Dec 31, 2009 at 09:59:51AM +0100, Stefani Seibold wrote:
    > Am Mittwoch, den 30.12.2009, 23:35 -0800 schrieb Dmitry Torokhov:
    >
    > > > I have a use case in linux/drivers/media/video/cx23885/cx23888-ir.c
    > > > right now.
    > > >
    > > > I have a hardware fifo that can hold up to 8 values, 17 bits each - and
    > > > the high bit of the value is a flag indicating if more data is in the
    > > > hardware fifo.
    > > >
    > > > The hardware fifo watermark for generating an interrupt is 4 or more
    > > > values in the hardware fifo.
    > > >
    > > > I use a kfifo that needs to be protected with a spinlock.
    > > >
    > > > It in much better in the IRQ context to drain the hardware fifo and then
    > > > put records in the kfifo all at once (or at least in groups of 8 or less
    > > > but usually greater than 1).
    > >
    > > Hmm, so there you have a local buffer that you fill by reading from the
    > > device word by word, then you copy that data over into fifo and then you
    > > upper layer again fetches that fifo as byte stream...
    > >
    > > I'd probably simply move the processing that you are doing in
    > > cx23888_ir_rx_read() into cx23888_ir_irq_handler() (since it is very
    > > simple) and then used kfifo in simple byte mode (since that is what
    > > upper layer seem to expect).
    > >
    >
    > Why using byte mode? He can use any type he like, the new macro based
    > implementation is record based! And a record can be a byte or any other
    > data type. Why do you discuss about code you didn't understand and want
    > not try? Why to discuss and waste time about less than 400 bytes of
    > library code? Terminate this useless discussion.
    >

    Yes, indeed.

    --
    Dmitry


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