| Message ID | 3a2404510b5f8b16ae3bb193982d70f158700b2b.1475571575.git.mylene.josserand@free-electrons.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, 4 Oct 2016 11:46:14 +0200 Mylène Josserand <mylene.josserand@free-electrons.com> wrote: > Add the case of a burst of 4 which is handled by the SoC. > > Signed-off-by: Mylène Josserand <mylene.josserand@free-electrons.com> > --- > drivers/dma/sun6i-dma.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/drivers/dma/sun6i-dma.c b/drivers/dma/sun6i-dma.c > index 8346199..0485204 100644 > --- a/drivers/dma/sun6i-dma.c > +++ b/drivers/dma/sun6i-dma.c > @@ -240,6 +240,8 @@ static inline s8 convert_burst(u32 maxburst) > switch (maxburst) { > case 1: > return 0; > + case 4: > + return 1; > case 8: > return 2; > default: > -- > 2.9.3 This patch has already been rejected by Maxime in the threads http://www.spinics.net/lists/dmaengine/msg08610.html and http://www.spinics.net/lists/dmaengine/msg08719.html I hope you will find the way he wants for this maxburst to be added.
Hello, On Tue, 4 Oct 2016 12:40:11 +0200, Jean-Francois Moine wrote: > > Add the case of a burst of 4 which is handled by the SoC. > > > > Signed-off-by: Mylène Josserand <mylene.josserand@free-electrons.com> > > --- > > drivers/dma/sun6i-dma.c | 2 ++ > > 1 file changed, 2 insertions(+) > > > > diff --git a/drivers/dma/sun6i-dma.c b/drivers/dma/sun6i-dma.c > > index 8346199..0485204 100644 > > --- a/drivers/dma/sun6i-dma.c > > +++ b/drivers/dma/sun6i-dma.c > > @@ -240,6 +240,8 @@ static inline s8 convert_burst(u32 maxburst) > > switch (maxburst) { > > case 1: > > return 0; > > + case 4: > > + return 1; > > case 8: > > return 2; > > default: > > -- > > 2.9.3 > > This patch has already been rejected by Maxime in the threads > http://www.spinics.net/lists/dmaengine/msg08610.html > and > http://www.spinics.net/lists/dmaengine/msg08719.html > > I hope you will find the way he wants for this maxburst to be added. I was about to reply to Mylene's e-mail, suggesting that she should add a comment in the code (and maybe in the commit log) to explain why this addition is needed, and also that even though the schematics say that value "1" (max burst size of 4 bytes) is reserved, it is in fact incorrect. The Allwinner BSP code is really using this value, and it's the value that makes audio work, so we believe the datasheet is simply incorrect. We already discussed it with Maxime, so I believe he should agree this time. But I would suggest to have such details explained in the commit log and in a comment in the code. Best regards, Thomas
On Tue, 4 Oct 2016 14:12:21 +0200 Thomas Petazzoni <thomas.petazzoni@free-electrons.com> wrote: > > > Add the case of a burst of 4 which is handled by the SoC. > > > > > > Signed-off-by: Mylène Josserand <mylene.josserand@free-electrons.com> > > > --- > > > drivers/dma/sun6i-dma.c | 2 ++ > > > 1 file changed, 2 insertions(+) > > > > > > diff --git a/drivers/dma/sun6i-dma.c b/drivers/dma/sun6i-dma.c > > > index 8346199..0485204 100644 > > > --- a/drivers/dma/sun6i-dma.c > > > +++ b/drivers/dma/sun6i-dma.c > > > @@ -240,6 +240,8 @@ static inline s8 convert_burst(u32 maxburst) > > > switch (maxburst) { > > > case 1: > > > return 0; > > > + case 4: > > > + return 1; > > > case 8: > > > return 2; > > > default: > > > -- > > > 2.9.3 > > > > This patch has already been rejected by Maxime in the threads > > http://www.spinics.net/lists/dmaengine/msg08610.html > > and > > http://www.spinics.net/lists/dmaengine/msg08719.html > > > > I hope you will find the way he wants for this maxburst to be added. > > I was about to reply to Mylene's e-mail, suggesting that she should add > a comment in the code (and maybe in the commit log) to explain why this > addition is needed, and also that even though the schematics say that > value "1" (max burst size of 4 bytes) is reserved, it is in fact > incorrect. The Allwinner BSP code is really using this value, and it's > the value that makes audio work, so we believe the datasheet is simply > incorrect. > > We already discussed it with Maxime, so I believe he should agree this > time. But I would suggest to have such details explained in the commit > log and in a comment in the code. Strange. Looking at the datasheets of the A23, A31, A33, A83T and H3 (these are the SoCs using the DMA sun6i), only the H3 can have 4 as the burst size (the doc is unclear for the A31). Well, I was submitting for the H3, Mylène is submitting for the A33. So, what about the A23, A31 and A83T?
On Tue, Oct 04, 2016 at 03:46:51PM +0200, Jean-Francois Moine wrote: > On Tue, 4 Oct 2016 14:12:21 +0200 > Thomas Petazzoni <thomas.petazzoni@free-electrons.com> wrote: > > > > > Add the case of a burst of 4 which is handled by the SoC. > > > > > > > > Signed-off-by: Mylène Josserand <mylene.josserand@free-electrons.com> > > > > --- > > > > drivers/dma/sun6i-dma.c | 2 ++ > > > > 1 file changed, 2 insertions(+) > > > > > > > > diff --git a/drivers/dma/sun6i-dma.c b/drivers/dma/sun6i-dma.c > > > > index 8346199..0485204 100644 > > > > --- a/drivers/dma/sun6i-dma.c > > > > +++ b/drivers/dma/sun6i-dma.c > > > > @@ -240,6 +240,8 @@ static inline s8 convert_burst(u32 maxburst) > > > > switch (maxburst) { > > > > case 1: > > > > return 0; > > > > + case 4: > > > > + return 1; > > > > case 8: > > > > return 2; > > > > default: > > > > -- > > > > 2.9.3 > > > > > > This patch has already been rejected by Maxime in the threads > > > http://www.spinics.net/lists/dmaengine/msg08610.html > > > and > > > http://www.spinics.net/lists/dmaengine/msg08719.html > > > > > > I hope you will find the way he wants for this maxburst to be added. > > > > I was about to reply to Mylene's e-mail, suggesting that she should add > > a comment in the code (and maybe in the commit log) to explain why this > > addition is needed, and also that even though the schematics say that > > value "1" (max burst size of 4 bytes) is reserved, it is in fact > > incorrect. The Allwinner BSP code is really using this value, and it's > > the value that makes audio work, so we believe the datasheet is simply > > incorrect. > > > > We already discussed it with Maxime, so I believe he should agree this > > time. But I would suggest to have such details explained in the commit > > log and in a comment in the code. > > Strange. Looking at the datasheets of the A23, A31, A33, A83T and H3 > (these are the SoCs using the DMA sun6i), only the H3 can have 4 as the > burst size (the doc is unclear for the A31). > > Well, I was submitting for the H3, Mylène is submitting for the A33. > So, what about the A23, A31 and A83T? Since these are device properties, I feel we should move this to DT. That way any new controller can have any variation based on the mood of hw designer that day and we can hopefully cope with it :-) But yes we would need to set the bursts supported in driver and allow above for supported bursts only.
diff --git a/drivers/dma/sun6i-dma.c b/drivers/dma/sun6i-dma.c index 8346199..0485204 100644 --- a/drivers/dma/sun6i-dma.c +++ b/drivers/dma/sun6i-dma.c @@ -240,6 +240,8 @@ static inline s8 convert_burst(u32 maxburst) switch (maxburst) { case 1: return 0; + case 4: + return 1; case 8: return 2; default:
Add the case of a burst of 4 which is handled by the SoC. Signed-off-by: Mylène Josserand <mylene.josserand@free-electrons.com> --- drivers/dma/sun6i-dma.c | 2 ++ 1 file changed, 2 insertions(+)