From: Angus Ainslie <angus@xxxxxxxx> Sent: Friday, March 22, 2019 9:20 PM
> Hi Lucas,
>
> On 2019-03-21 20:36, Andy Duan wrote:
> > This reverts commit 25aaa75df1e6 (dmaengine: imx-sdma: add clock ratio
> > 1:1 check) due to break SDMA function on i.MX6SX platform.
> >
> > Log:
> > imx-sdma 20ec000.sdma: Timeout waiting for CH0 ready
> >
> > Fixes: 25aaa75df1e6 (dmaengine: imx-sdma: add clock ratio 1:1 check)
> > Signed-off-by: Fugang Duan <fugang.duan@xxxxxxx>
> > ---
> > drivers/dma/imx-sdma.c | 18 ++++--------------
> > 1 file changed, 4 insertions(+), 14 deletions(-)
> >
> > diff --git a/drivers/dma/imx-sdma.c b/drivers/dma/imx-sdma.c index
> > 5f3c137..7fae4bf 100644
> > --- a/drivers/dma/imx-sdma.c
> > +++ b/drivers/dma/imx-sdma.c
> > @@ -441,8 +441,6 @@ struct sdma_engine {
> > unsigned int irq;
> > dma_addr_t bd0_phys;
> > struct sdma_buffer_descriptor *bd0;
> > - /* clock ratio for AHB:SDMA core. 1:1 is 1, 2:1 is 0*/
> > - bool clk_ratio;
> > };
> >
> > static int sdma_config_write(struct dma_chan *chan, @@ -665,11 +663,8
> > @@ static int sdma_run_channel0(struct sdma_engine
> > *sdma)
> > dev_err(sdma->dev, "Timeout waiting for CH0 ready\n");
> >
> > /* Set bits of CONFIG register with dynamic context switching */
> > - reg = readl(sdma->regs + SDMA_H_CONFIG);
> > - if ((reg & SDMA_H_CONFIG_CSM) == 0) {
> > - reg |= SDMA_H_CONFIG_CSM;
> > - writel_relaxed(reg, sdma->regs + SDMA_H_CONFIG);
> > - }
> > + if (readl(sdma->regs + SDMA_H_CONFIG) == 0)
> > + writel_relaxed(SDMA_H_CONFIG_CSM, sdma->regs +
> SDMA_H_CONFIG);
> >
> > return ret;
> > }
> > @@ -1852,9 +1847,6 @@ static int sdma_init(struct sdma_engine *sdma)
> > if (ret)
> > goto disable_clk_ipg;
> >
> > - if (clk_get_rate(sdma->clk_ahb) == clk_get_rate(sdma->clk_ipg))
> > - sdma->clk_ratio = 1;
> > -
> > /* Be sure SDMA has not started yet */
> > writel_relaxed(0, sdma->regs + SDMA_H_C0PTR);
> >
> > @@ -1895,10 +1887,8 @@ static int sdma_init(struct sdma_engine *sdma)
> > writel_relaxed(0x4050, sdma->regs + SDMA_CHN0ADDR);
> >
> > /* Set bits of CONFIG register but with static context switching */
> > - if (sdma->clk_ratio)
> > - writel_relaxed(SDMA_H_CONFIG_ACR, sdma->regs +
> SDMA_H_CONFIG);
> > - else
> > - writel_relaxed(0, sdma->regs + SDMA_H_CONFIG);
> > + /* FIXME: Check whether to set ACR bit depending on clock ratios */
> > + writel_relaxed(0, sdma->regs + SDMA_H_CONFIG);
>
> It looks like the automated check breaks some imx chips. Are you ok if I
> resubmit with the original devicetree switch ?
>
> I guess another way would be to have a different compatible string and have
> some kind of "quirks".
>
> Thanks
> Angus
Since current SDMA driver break imx legacy platforms, please apply the patch firstly.
Then we can submit the correct patch for clock ratio 1:1 check.
Andy
>
> >
> > writel_relaxed(ccb_phys, sdma->regs + SDMA_H_C0PTR);
