Hi Vinod, > -----Original Message----- > From: Vinod Koul [mailto:vinod.koul@xxxxxxxxx] > Sent: Tuesday, February 23, 2016 8:42 AM > To: Appana Durga Kedareswara Rao > Cc: dan.j.williams@xxxxxxxxx; Michal Simek; Soren Brinkmann; Appana Durga > Kedareswara Rao; moritz.fischer@xxxxxxxxx; > laurent.pinchart@xxxxxxxxxxxxxxxx; luis@xxxxxxxxxxxxxxxxx; Anirudha > Sarangi; dmaengine@xxxxxxxxxxxxxxx; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; > linux-kernel@xxxxxxxxxxxxxxx > Subject: Re: [PATCH v2 4/4] dmaengine: xilinx_vdma: Improve channel idle > checking > > On Mon, Feb 22, 2016 at 11:24:37AM +0530, Kedareswara rao Appana wrote: > > This patch improves the channel idle cheking by introduing > ^^^^^^^^^ > typo Ok will fix. > > > a new varibale in chan private structure. > ^^^^^^^ > here too :( Ok will fix. > > and there is no description how this improvement is achieved and why Ok will give detailed explanation in the next version of the patch. Regards, Kedar. > > > > Signed-off-by: Kedareswara rao Appana <appanad@xxxxxxxxxx> > > --- > > Changes for v2: > > ---> splitted the changes into multiple patches. > > > > drivers/dma/xilinx/xilinx_vdma.c | 41 > > ++++++++-------------------------------- > > 1 file changed, 8 insertions(+), 33 deletions(-) > > > > diff --git a/drivers/dma/xilinx/xilinx_vdma.c > > b/drivers/dma/xilinx/xilinx_vdma.c > > index 8db07f7..51686d1 100644 > > --- a/drivers/dma/xilinx/xilinx_vdma.c > > +++ b/drivers/dma/xilinx/xilinx_vdma.c > > @@ -202,6 +202,7 @@ struct xilinx_vdma_tx_descriptor { > > * @has_sg: Support scatter transfers > > * @genlock: Support genlock mode > > * @err: Channel has errors > > + * @idle: Check for channel idle > > * @tasklet: Cleanup work after irq > > * @config: Device configuration info > > * @flush_on_fsync: Flush on Frame sync @@ -225,6 +226,7 @@ struct > > xilinx_vdma_chan { > > bool has_sg; > > bool genlock; > > bool err; > > + bool idle; > > struct tasklet_struct tasklet; > > struct xilinx_vdma_config config; > > bool flush_on_fsync; > > @@ -519,32 +521,6 @@ static enum dma_status > > xilinx_vdma_tx_status(struct dma_chan *dchan, } > > > > /** > > - * xilinx_vdma_is_running - Check if VDMA channel is running > > - * @chan: Driver specific VDMA channel > > - * > > - * Return: '1' if running, '0' if not. > > - */ > > -static bool xilinx_vdma_is_running(struct xilinx_vdma_chan *chan) -{ > > - return !(vdma_ctrl_read(chan, XILINX_VDMA_REG_DMASR) & > > - XILINX_VDMA_DMASR_HALTED) && > > - (vdma_ctrl_read(chan, XILINX_VDMA_REG_DMACR) & > > - XILINX_VDMA_DMACR_RUNSTOP); > > -} > > - > > -/** > > - * xilinx_vdma_is_idle - Check if VDMA channel is idle > > - * @chan: Driver specific VDMA channel > > - * > > - * Return: '1' if idle, '0' if not. > > - */ > > -static bool xilinx_vdma_is_idle(struct xilinx_vdma_chan *chan) -{ > > - return vdma_ctrl_read(chan, XILINX_VDMA_REG_DMASR) & > > - XILINX_VDMA_DMASR_IDLE; > > -} > > - > > -/** > > * xilinx_vdma_halt - Halt VDMA channel > > * @chan: Driver specific VDMA channel > > */ > > @@ -614,6 +590,9 @@ static void xilinx_vdma_start_transfer(struct > xilinx_vdma_chan *chan) > > if (list_empty(&chan->pending_list)) > > return; > > > > + if (!chan->idle) > > + return; > > + > > desc = list_first_entry(&chan->pending_list, > > struct xilinx_vdma_tx_descriptor, node); > > tail_desc = list_last_entry(&chan->pending_list, > > @@ -622,13 +601,6 @@ static void xilinx_vdma_start_transfer(struct > xilinx_vdma_chan *chan) > > tail_segment = list_last_entry(&tail_desc->segments, > > struct xilinx_vdma_tx_segment, node); > > > > - /* If it is SG mode and hardware is busy, cannot submit */ > > - if (chan->has_sg && xilinx_vdma_is_running(chan) && > > - !xilinx_vdma_is_idle(chan)) { > > - dev_dbg(chan->dev, "DMA controller still busy\n"); > > - return; > > - } > > - > > /* > > * If hardware is idle, then all descriptors on the running lists are > > * done, start new transfers > > @@ -708,6 +680,7 @@ static void xilinx_vdma_start_transfer(struct > > xilinx_vdma_chan *chan) > > > > list_splice_tail_init(&chan->pending_list, &chan->active_list); > > chan->desc_pendingcount = 0; > > + chan->idle = false; > > } > > > > /** > > @@ -854,6 +827,7 @@ static irqreturn_t xilinx_vdma_irq_handler(int irq, void > *data) > > if (status & XILINX_VDMA_DMASR_FRM_CNT_IRQ) { > > spin_lock(&chan->lock); > > xilinx_vdma_complete_descriptor(chan); > > + chan->idle = true; > > xilinx_vdma_start_transfer(chan); > > spin_unlock(&chan->lock); > > } > > @@ -1212,6 +1186,7 @@ static int xilinx_vdma_chan_probe(struct > > xilinx_vdma_device *xdev, > > > > list_add_tail(&chan->common.device_node, &xdev- > >common.channels); > > xdev->chan[chan->id] = chan; > > + chan->idle = true; > > > > /* Reset the channel */ > > err = xilinx_vdma_chan_reset(chan); > > -- > > 2.1.2 > > > > -- > ~Vinod -- To unsubscribe from this list: send the line "unsubscribe dmaengine" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
