| Message ID | 20200112173006.29863-3-digetx@gmail.com |
|---|---|
| State | Changes Requested |
| Headers | show |
| Series | NVIDIA Tegra APB DMA driver fixes and improvements | expand |
On 12/01/2020 17:29, Dmitry Osipenko wrote: > The ISR tasklet could be kept scheduled after DMA transfer termination, > let's add synchronization callback which blocks until tasklet is finished. > > Signed-off-by: Dmitry Osipenko <digetx@gmail.com> > --- > drivers/dma/tegra20-apb-dma.c | 8 ++++++++ > 1 file changed, 8 insertions(+) > > diff --git a/drivers/dma/tegra20-apb-dma.c b/drivers/dma/tegra20-apb-dma.c > index 319f31d27014..664e9c5df3ba 100644 > --- a/drivers/dma/tegra20-apb-dma.c > +++ b/drivers/dma/tegra20-apb-dma.c > @@ -798,6 +798,13 @@ static int tegra_dma_terminate_all(struct dma_chan *dc) > return 0; > } > > +static void tegra_dma_synchronize(struct dma_chan *dc) > +{ > + struct tegra_dma_channel *tdc = to_tegra_dma_chan(dc); > + > + tasklet_kill(&tdc->tasklet); > +} > + Wouldn't there need to be some clean-up here? If the tasklet is scheduled, seems that there would be some other house-keeping that needs to be done after killing it. Jon
14.01.2020 18:15, Jon Hunter пишет: > > On 12/01/2020 17:29, Dmitry Osipenko wrote: >> The ISR tasklet could be kept scheduled after DMA transfer termination, >> let's add synchronization callback which blocks until tasklet is finished. >> >> Signed-off-by: Dmitry Osipenko <digetx@gmail.com> >> --- >> drivers/dma/tegra20-apb-dma.c | 8 ++++++++ >> 1 file changed, 8 insertions(+) >> >> diff --git a/drivers/dma/tegra20-apb-dma.c b/drivers/dma/tegra20-apb-dma.c >> index 319f31d27014..664e9c5df3ba 100644 >> --- a/drivers/dma/tegra20-apb-dma.c >> +++ b/drivers/dma/tegra20-apb-dma.c >> @@ -798,6 +798,13 @@ static int tegra_dma_terminate_all(struct dma_chan *dc) >> return 0; >> } >> >> +static void tegra_dma_synchronize(struct dma_chan *dc) >> +{ >> + struct tegra_dma_channel *tdc = to_tegra_dma_chan(dc); >> + >> + tasklet_kill(&tdc->tasklet); >> +} >> + > > Wouldn't there need to be some clean-up here? If the tasklet is > scheduled, seems that there would be some other house-keeping that needs > to be done after killing it. I'm not seeing anything to clean-up, could you please clarify?
On 14/01/2020 21:02, Dmitry Osipenko wrote: > 14.01.2020 18:15, Jon Hunter пишет: >> >> On 12/01/2020 17:29, Dmitry Osipenko wrote: >>> The ISR tasklet could be kept scheduled after DMA transfer termination, >>> let's add synchronization callback which blocks until tasklet is finished. >>> >>> Signed-off-by: Dmitry Osipenko <digetx@gmail.com> >>> --- >>> drivers/dma/tegra20-apb-dma.c | 8 ++++++++ >>> 1 file changed, 8 insertions(+) >>> >>> diff --git a/drivers/dma/tegra20-apb-dma.c b/drivers/dma/tegra20-apb-dma.c >>> index 319f31d27014..664e9c5df3ba 100644 >>> --- a/drivers/dma/tegra20-apb-dma.c >>> +++ b/drivers/dma/tegra20-apb-dma.c >>> @@ -798,6 +798,13 @@ static int tegra_dma_terminate_all(struct dma_chan *dc) >>> return 0; >>> } >>> >>> +static void tegra_dma_synchronize(struct dma_chan *dc) >>> +{ >>> + struct tegra_dma_channel *tdc = to_tegra_dma_chan(dc); >>> + >>> + tasklet_kill(&tdc->tasklet); >>> +} >>> + >> >> Wouldn't there need to be some clean-up here? If the tasklet is >> scheduled, seems that there would be some other house-keeping that needs >> to be done after killing it. > > I'm not seeing anything to clean-up, could you please clarify? Clean-up with regard to the descriptors. I was concerned if you will the tasklet the necessary clean-up of the descriptors is not handled. Jon
On 15/01/2020 09:18, Jon Hunter wrote: > > On 14/01/2020 21:02, Dmitry Osipenko wrote: >> 14.01.2020 18:15, Jon Hunter пишет: >>> >>> On 12/01/2020 17:29, Dmitry Osipenko wrote: >>>> The ISR tasklet could be kept scheduled after DMA transfer termination, >>>> let's add synchronization callback which blocks until tasklet is finished. >>>> >>>> Signed-off-by: Dmitry Osipenko <digetx@gmail.com> >>>> --- >>>> drivers/dma/tegra20-apb-dma.c | 8 ++++++++ >>>> 1 file changed, 8 insertions(+) >>>> >>>> diff --git a/drivers/dma/tegra20-apb-dma.c b/drivers/dma/tegra20-apb-dma.c >>>> index 319f31d27014..664e9c5df3ba 100644 >>>> --- a/drivers/dma/tegra20-apb-dma.c >>>> +++ b/drivers/dma/tegra20-apb-dma.c >>>> @@ -798,6 +798,13 @@ static int tegra_dma_terminate_all(struct dma_chan *dc) >>>> return 0; >>>> } >>>> >>>> +static void tegra_dma_synchronize(struct dma_chan *dc) >>>> +{ >>>> + struct tegra_dma_channel *tdc = to_tegra_dma_chan(dc); >>>> + >>>> + tasklet_kill(&tdc->tasklet); >>>> +} >>>> + >>> >>> Wouldn't there need to be some clean-up here? If the tasklet is >>> scheduled, seems that there would be some other house-keeping that needs >>> to be done after killing it. >> >> I'm not seeing anything to clean-up, could you please clarify? > > Clean-up with regard to the descriptors. I was concerned if you will the > tasklet the necessary clean-up of the descriptors is not handled. Ah I see that tasklet_kill, unlike tasklet_kill_immediate, does wait for the tasklet to run if scheduled. OK, then this should be fine. Acked-by: Jon Hunter <jonathanh@nvidia.com> Cheers Jon
diff --git a/drivers/dma/tegra20-apb-dma.c b/drivers/dma/tegra20-apb-dma.c index 319f31d27014..664e9c5df3ba 100644 --- a/drivers/dma/tegra20-apb-dma.c +++ b/drivers/dma/tegra20-apb-dma.c @@ -798,6 +798,13 @@ static int tegra_dma_terminate_all(struct dma_chan *dc) return 0; } +static void tegra_dma_synchronize(struct dma_chan *dc) +{ + struct tegra_dma_channel *tdc = to_tegra_dma_chan(dc); + + tasklet_kill(&tdc->tasklet); +} + static unsigned int tegra_dma_sg_bytes_xferred(struct tegra_dma_channel *tdc, struct tegra_dma_sg_req *sg_req) { @@ -1506,6 +1513,7 @@ static int tegra_dma_probe(struct platform_device *pdev) tdma->dma_dev.residue_granularity = DMA_RESIDUE_GRANULARITY_BURST; tdma->dma_dev.device_config = tegra_dma_slave_config; tdma->dma_dev.device_terminate_all = tegra_dma_terminate_all; + tdma->dma_dev.device_synchronize = tegra_dma_synchronize; tdma->dma_dev.device_tx_status = tegra_dma_tx_status; tdma->dma_dev.device_issue_pending = tegra_dma_issue_pending;
The ISR tasklet could be kept scheduled after DMA transfer termination, let's add synchronization callback which blocks until tasklet is finished. Signed-off-by: Dmitry Osipenko <digetx@gmail.com> --- drivers/dma/tegra20-apb-dma.c | 8 ++++++++ 1 file changed, 8 insertions(+)