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    SubjectRe: [PATCH v4 2/7] dmaengine: xilinx_dma: in axidma slave_sg and dma_cylic mode align split descriptors
    On Thu, Aug 30, 2018 at 3:27 PM Vinod <vkoul@kernel.org> wrote:
    >
    > On 30-08-18, 10:11, Andrea Merello wrote:
    > > On Wed, Aug 29, 2018 at 10:12 AM Andrea Merello
    > > <andrea.merello@gmail.com> wrote:
    > > >
    > > > On Mon, Aug 27, 2018 at 7:30 AM Vinod <vkoul@kernel.org> wrote:
    > > > >
    > > > > On 02-08-18, 16:10, Andrea Merello wrote:
    > > > >
    > > > > s/cylic/cyclic in patch title
    > > >
    > > > OK
    > > >
    > > > > > Whenever a single or cyclic transaction is prepared, the driver
    > > > > > could eventually split it over several SG descriptors in order
    > > > > > to deal with the HW maximum transfer length.
    > > > > >
    > > > > > This could end up in DMA operations starting from a misaligned
    > > > > > address. This seems fatal for the HW if DRE is not enabled.
    > > > >
    > > > > DRE?
    > > >
    > > > Stands for "Data Realignment Engine". I will add this string nearby
    > > > the acronym..
    > > >
    > > > > >
    > > > > > This patch eventually adjusts the transfer size in order to make sure
    > > > > > all operations start from an aligned address.
    > > > > >
    > > > > > Cc: Radhey Shyam Pandey <radhey.shyam.pandey@xilinx.com>
    > > > > > Signed-off-by: Andrea Merello <andrea.merello@gmail.com>
    > > > > > Reviewed-by: Radhey Shyam Pandey <radhey.shyam.pandey@xilinx.com>
    > > > > > ---
    > > > > > Changes in v2:
    > > > > > - don't introduce copy_mask field, rather rely on already-esistent
    > > > > > copy_align field. Suggested by Radhey Shyam Pandey
    > > > > > - reword title
    > > > > > Changes in v3:
    > > > > > - fix bug introduced in v2: wrong copy size when DRE is enabled
    > > > > > - use implementation suggested by Radhey Shyam Pandey
    > > > > > Changes in v4:
    > > > > > - rework on the top of 1/6
    > > > > > ---
    > > > > > drivers/dma/xilinx/xilinx_dma.c | 22 ++++++++++++++++++----
    > > > > > 1 file changed, 18 insertions(+), 4 deletions(-)
    > > > > >
    > > > > > diff --git a/drivers/dma/xilinx/xilinx_dma.c b/drivers/dma/xilinx/xilinx_dma.c
    > > > > > index a3aaa0e34cc7..aaa6de8a70e4 100644
    > > > > > --- a/drivers/dma/xilinx/xilinx_dma.c
    > > > > > +++ b/drivers/dma/xilinx/xilinx_dma.c
    > > > > > @@ -954,15 +954,28 @@ static int xilinx_dma_alloc_chan_resources(struct dma_chan *dchan)
    > > > > >
    > > > > > /**
    > > > > > * xilinx_dma_calc_copysize - Calculate the amount of data to copy
    > > > > > + * @chan: Driver specific DMA channel
    > > > > > * @size: Total data that needs to be copied
    > > > > > * @done: Amount of data that has been already copied
    > > > > > *
    > > > > > * Return: Amount of data that has to be copied
    > > > > > */
    > > > > > -static int xilinx_dma_calc_copysize(int size, int done)
    > > > > > +static int xilinx_dma_calc_copysize(struct xilinx_dma_chan *chan,
    > > > > > + int size, int done)
    > > > >
    > > > > please align with opening brace
    > > >
    > > > OK
    > >
    > > Sorry for getting back on this.
    > > I've checked it, but it seems already aligned with opening brace in
    > > the original e-mail text I've sent. (4 tabs + 4 spaces).
    >
    > Okay, please see that code looks fine, I will check after I apply

    Yes, I confirm that here the code does look fine: the 2nd line is
    aligned with opening brace indeed.

    Do you want I produce now a v5 with all the other fixes you asked for
    (basically commit message fixes), or you are going to apply/check this
    one and should I wait for that?

    > --
    > ~Vinod

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