| Message ID | 20200528222401.26941-8-Sergey.Semin@baikalelectronics.ru (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | dmaengine: dw: Take Baikal-T1 SoC DW DMAC peculiarities into account | expand |
On Fri, May 29, 2020 at 01:23:57AM +0300, Serge Semin wrote: > Maximum block size DW DMAC configuration corresponds to the max segment > size DMA parameter in the DMA core subsystem notation. Lets set it with a > value specific to the probed DW DMA controller. It shall help the DMA > clients to create size-optimized SG-list items for the controller. This in > turn will cause less dw_desc allocations, less LLP reinitializations, > better DMA device performance. Yes, something like that for time being, thanks! Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> > Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru> > Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru> > Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> > Cc: Arnd Bergmann <arnd@arndb.de> > Cc: Rob Herring <robh+dt@kernel.org> > Cc: linux-mips@vger.kernel.org > Cc: devicetree@vger.kernel.org > > --- > > Changelog v2: > - This is a new patch created in place of the dropped one: > "dmaengine: dw: Add LLP and block size config accessors". > > Changelog v3: > - Use the block_size found for the very first channel instead of looking for > the maximum of maximum block sizes. > - Don't define device-specific device_dma_parameters object, since it has > already been defined by the platform device core. > --- > drivers/dma/dw/core.c | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/drivers/dma/dw/core.c b/drivers/dma/dw/core.c > index 33e99d95b3d3..fb95920c429e 100644 > --- a/drivers/dma/dw/core.c > +++ b/drivers/dma/dw/core.c > @@ -1229,6 +1229,13 @@ int do_dma_probe(struct dw_dma_chip *chip) > BIT(DMA_MEM_TO_MEM); > dw->dma.residue_granularity = DMA_RESIDUE_GRANULARITY_BURST; > > + /* > + * For now there is no hardware with non uniform maximum block size > + * across all of the device channels, so we set the maximum segment > + * size as the block size found for the very first channel. > + */ > + dma_set_max_seg_size(dw->dma.dev, dw->chan[0].block_size); > + > err = dma_async_device_register(&dw->dma); > if (err) > goto err_dma_register; > -- > 2.26.2 >
diff --git a/drivers/dma/dw/core.c b/drivers/dma/dw/core.c index 33e99d95b3d3..fb95920c429e 100644 --- a/drivers/dma/dw/core.c +++ b/drivers/dma/dw/core.c @@ -1229,6 +1229,13 @@ int do_dma_probe(struct dw_dma_chip *chip) BIT(DMA_MEM_TO_MEM); dw->dma.residue_granularity = DMA_RESIDUE_GRANULARITY_BURST; + /* + * For now there is no hardware with non uniform maximum block size + * across all of the device channels, so we set the maximum segment + * size as the block size found for the very first channel. + */ + dma_set_max_seg_size(dw->dma.dev, dw->chan[0].block_size); + err = dma_async_device_register(&dw->dma); if (err) goto err_dma_register;
Maximum block size DW DMAC configuration corresponds to the max segment size DMA parameter in the DMA core subsystem notation. Lets set it with a value specific to the probed DW DMA controller. It shall help the DMA clients to create size-optimized SG-list items for the controller. This in turn will cause less dw_desc allocations, less LLP reinitializations, better DMA device performance. Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru> Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Rob Herring <robh+dt@kernel.org> Cc: linux-mips@vger.kernel.org Cc: devicetree@vger.kernel.org --- Changelog v2: - This is a new patch created in place of the dropped one: "dmaengine: dw: Add LLP and block size config accessors". Changelog v3: - Use the block_size found for the very first channel instead of looking for the maximum of maximum block sizes. - Don't define device-specific device_dma_parameters object, since it has already been defined by the platform device core. --- drivers/dma/dw/core.c | 7 +++++++ 1 file changed, 7 insertions(+)