[alsa-devel] [PATCH v4 4/4] ASoC: SAMSUNG: Add I2S0 internal dma driver

[Jassi Brar]

On Fri, Jul 1, 2011 at 7:18 AM, Sangbeom Kim <sbkim73 at samsung.com> wrote:

> +static void idma_control(int op)
> +{
> +       u32 val = readl(idma.regs + I2SAHB);
> +
> +       spin_lock(&idma.lock);
> +
> +       switch (op) {
> +       case LPAM_DMA_START:
> +               val |= (AHB_INTENLVL0 | AHB_DMAEN);
> +               break;
> +       case LPAM_DMA_STOP:
> +               val &= ~(AHB_INTENLVL0 | AHB_DMAEN);
> +               break;
> +       default:
> +               return;
Need to release the lock before return.
This is not the showstopper for this revision.
> +       }
> +
> +       writel(val, idma.regs + I2SAHB);
> +       spin_unlock(&idma.lock);
> +}
> +

......

> +static irqreturn_t iis_irq(int irqno, void *dev_id)
> +{
> +       struct idma_ctrl *prtd = (struct idma_ctrl *)dev_id;
> +       u32 iiscon, iisahb, val, addr;
> +
> +       iisahb  = readl(idma.regs + I2SAHB);
> +       iiscon  = readl(idma.regs + I2SCON);
> +
> +       val = (iisahb & AHB_LVL0INT) ? AHB_CLRLVL0INT : 0;
> +
> +       if (val) {
> +               iisahb |= val;
> +               writel(iisahb, idma.regs + I2SAHB);
> +
> +               addr = readl(idma.regs + I2SLVL0ADDR) - idma.lp_tx_addr;
> +               addr += prtd->periodsz;
> +               addr %= prtd->period;
> +               addr += idma.lp_tx_addr;
Dear, out of 4 revisions, 3(including current) got it wrong at this
important point.
Ok write it like below
               addr = readl(idma.regs + I2SLVL0ADDR) - idma.lp_tx_addr;
               addr += prtd->periodsz;
               addr %= (prtd->end - prtd->start);   // <------ Note
               addr += idma.lp_tx_addr;
> +
> +               writel(addr, idma.regs + I2SLVL0ADDR);
> +
> +               if (prtd->cb)
> +                       prtd->cb(prtd->token, prtd->period);
> +       }
> +
> +       return IRQ_HANDLED;
> +}
> +