| Message ID | 20171019221308.18707-1-digetx@gmail.com |
|---|---|
| State | Deferred |
| Headers | show |
| Series | [v2] dmaengine: tegra-apb: Support non-flow controlled slave configuration | expand |
On 20.10.2017 01:13, Dmitry Osipenko wrote: > This allows DMA client to issue a non-flow controlled TX. In particular > it is needed for the fuse driver that reads fuse registers using APBDMA > to workaround a HW bug that results in hang when CPU and DMA perform > simultaneous access to fuse peripheral. > > Signed-off-by: Dmitry Osipenko <digetx@gmail.com> > Reviewed-by: Jon Hunter <jonathanh@nvidia.com> Vinod, are you going to apply this patch for 4.15? -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Tue, Nov 14, 2017 at 02:23:07PM +0300, Dmitry Osipenko wrote: > On 20.10.2017 01:13, Dmitry Osipenko wrote: > > This allows DMA client to issue a non-flow controlled TX. In particular > > it is needed for the fuse driver that reads fuse registers using APBDMA > > to workaround a HW bug that results in hang when CPU and DMA perform > > simultaneous access to fuse peripheral. > > > > Signed-off-by: Dmitry Osipenko <digetx@gmail.com> > > Reviewed-by: Jon Hunter <jonathanh@nvidia.com> > > Vinod, are you going to apply this patch for 4.15? Sorry I dont seem to have this one in my queue and dont see it applied, not sure why. Can you guys resend please
On 15.11.2017 18:54, Vinod Koul wrote: > On Tue, Nov 14, 2017 at 02:23:07PM +0300, Dmitry Osipenko wrote: >> On 20.10.2017 01:13, Dmitry Osipenko wrote: >>> This allows DMA client to issue a non-flow controlled TX. In particular >>> it is needed for the fuse driver that reads fuse registers using APBDMA >>> to workaround a HW bug that results in hang when CPU and DMA perform >>> simultaneous access to fuse peripheral. >>> >>> Signed-off-by: Dmitry Osipenko <digetx@gmail.com> >>> Reviewed-by: Jon Hunter <jonathanh@nvidia.com> >> >> Vinod, are you going to apply this patch for 4.15? > > Sorry I dont seem to have this one in my queue and dont see it applied, not > sure why. Can you guys resend please > No problem, re-sent. -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/dma/tegra20-apb-dma.c b/drivers/dma/tegra20-apb-dma.c index b9d75a54c896..9a558e30c461 100644 --- a/drivers/dma/tegra20-apb-dma.c +++ b/drivers/dma/tegra20-apb-dma.c @@ -353,7 +353,8 @@ static int tegra_dma_slave_config(struct dma_chan *dc, } memcpy(&tdc->dma_sconfig, sconfig, sizeof(*sconfig)); - if (tdc->slave_id == TEGRA_APBDMA_SLAVE_ID_INVALID) { + if (tdc->slave_id == TEGRA_APBDMA_SLAVE_ID_INVALID && + sconfig->device_fc) { if (sconfig->slave_id > TEGRA_APBDMA_CSR_REQ_SEL_MASK) return -EINVAL; tdc->slave_id = sconfig->slave_id; @@ -970,8 +971,13 @@ static struct dma_async_tx_descriptor *tegra_dma_prep_slave_sg( TEGRA_APBDMA_AHBSEQ_WRAP_SHIFT; ahb_seq |= TEGRA_APBDMA_AHBSEQ_BUS_WIDTH_32; - csr |= TEGRA_APBDMA_CSR_ONCE | TEGRA_APBDMA_CSR_FLOW; - csr |= tdc->slave_id << TEGRA_APBDMA_CSR_REQ_SEL_SHIFT; + csr |= TEGRA_APBDMA_CSR_ONCE; + + if (tdc->slave_id != TEGRA_APBDMA_SLAVE_ID_INVALID) { + csr |= TEGRA_APBDMA_CSR_FLOW; + csr |= tdc->slave_id << TEGRA_APBDMA_CSR_REQ_SEL_SHIFT; + } + if (flags & DMA_PREP_INTERRUPT) csr |= TEGRA_APBDMA_CSR_IE_EOC; @@ -1110,10 +1116,13 @@ static struct dma_async_tx_descriptor *tegra_dma_prep_dma_cyclic( TEGRA_APBDMA_AHBSEQ_WRAP_SHIFT; ahb_seq |= TEGRA_APBDMA_AHBSEQ_BUS_WIDTH_32; - csr |= TEGRA_APBDMA_CSR_FLOW; + if (tdc->slave_id != TEGRA_APBDMA_SLAVE_ID_INVALID) { + csr |= TEGRA_APBDMA_CSR_FLOW; + csr |= tdc->slave_id << TEGRA_APBDMA_CSR_REQ_SEL_SHIFT; + } + if (flags & DMA_PREP_INTERRUPT) csr |= TEGRA_APBDMA_CSR_IE_EOC; - csr |= tdc->slave_id << TEGRA_APBDMA_CSR_REQ_SEL_SHIFT; apb_seq |= TEGRA_APBDMA_APBSEQ_WRAP_WORD_1;