On Sun, Feb 15, 2015 at 10:00:35AM +0800, Robin Gong wrote: > Below comments got from Page4724 of Reference Manual of i.mx6q: > http://cache.freescale.com/files/32bit/doc/ref_manual/IMX6DQRM.pdf > > --"Static context mode should be used for the first channel called > after reset to ensure that the all context RAM for that channel is > initialized during the context SAVE phase when the channel is > done or yields. Subsequent calls to the same channel or > different channels may use any of the dynamic context modes. > This will ensure that all context locations for the bootload > channel are initialized, and prevent undefined values in context > RAM from being loaded during the context restore if the > channel is re-started later" > > Unfortunately, the rule was broken by commit(5b28aa319bba96987316425a1131813d87cbab35) > .This patch just take them back. Applied, thanks -- ~Vinod > > Signed-off-by: Robin Gong <b38343@xxxxxxxxxxxxx> > --- > drivers/dma/imx-sdma.c | 7 ++++--- > 1 file changed, 4 insertions(+), 3 deletions(-) > > diff --git a/drivers/dma/imx-sdma.c b/drivers/dma/imx-sdma.c > index d0df198..644cfa0 100644 > --- a/drivers/dma/imx-sdma.c > +++ b/drivers/dma/imx-sdma.c > @@ -531,6 +531,10 @@ 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 */ > + if (readl(sdma->regs + SDMA_H_CONFIG) == 0) > + writel_relaxed(SDMA_H_CONFIG_CSM, sdma->regs + SDMA_H_CONFIG); > + > return ret ? 0 : -ETIMEDOUT; > } > > @@ -1401,9 +1405,6 @@ static int sdma_init(struct sdma_engine *sdma) > > writel_relaxed(ccb_phys, sdma->regs + SDMA_H_C0PTR); > > - /* Set bits of CONFIG register with given context switching mode */ > - writel_relaxed(SDMA_H_CONFIG_CSM, sdma->regs + SDMA_H_CONFIG); > - > /* Initializes channel's priorities */ > sdma_set_channel_priority(&sdma->channel[0], 7); > > -- > 1.9.1 > > -- > 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 -- -- 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
