Hi Andy,
Thank you for the patch.
On Mon, Aug 17, 2020 at 07:07:29PM +0300, Andy Shevchenko wrote:
> We may use special helper macro to poll IO till condition or timeout occurs.
>
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
> ---
> v2: wrapped long line (Bingbu)
> drivers/media/pci/intel/ipu3/ipu3-cio2.c | 18 +++++++++---------
> 1 file changed, 9 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/media/pci/intel/ipu3/ipu3-cio2.c b/drivers/media/pci/intel/ipu3/ipu3-cio2.c
> index 36b4c7730f43..7bcde3ba8f6e 100644
> --- a/drivers/media/pci/intel/ipu3/ipu3-cio2.c
> +++ b/drivers/media/pci/intel/ipu3/ipu3-cio2.c
> @@ -14,6 +14,7 @@
>
> #include <linux/delay.h>
> #include <linux/interrupt.h>
> +#include <linux/iopoll.h>
> #include <linux/module.h>
> #include <linux/pci.h>
> #include <linux/pfn.h>
> @@ -507,8 +508,10 @@ static int cio2_hw_init(struct cio2_device *cio2, struct cio2_queue *q)
>
> static void cio2_hw_exit(struct cio2_device *cio2, struct cio2_queue *q)
> {
> - void __iomem *base = cio2->base;
> - unsigned int i, maxloops = 1000;
> + void __iomem *const base = cio2->base;
> + unsigned int i;
> + u32 value;
> + int ret;
>
> /* Disable CSI receiver and MIPI backend devices */
> writel(0, q->csi_rx_base + CIO2_REG_IRQCTRL_MASK);
> @@ -518,13 +521,10 @@ static void cio2_hw_exit(struct cio2_device *cio2, struct cio2_queue *q)
>
> /* Halt DMA */
> writel(0, base + CIO2_REG_CDMAC0(CIO2_DMA_CHAN));
> - do {
> - if (readl(base + CIO2_REG_CDMAC0(CIO2_DMA_CHAN)) &
> - CIO2_CDMAC0_DMA_HALTED)
> - break;
> - usleep_range(1000, 2000);
> - } while (--maxloops);
> - if (!maxloops)
> + ret = readl_poll_timeout(base + CIO2_REG_CDMAC0(CIO2_DMA_CHAN),
> + value, value & CIO2_CDMAC0_DMA_HALTED,
> + 4000, 2000000);
I had to read the implementation of readl_poll_timeout() to see why you
turned [1000, 2000] to 4000. This effectively becomes [1000, 4000] which
should be fine.
Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
> + if (ret)
> dev_err(&cio2->pci_dev->dev,
> "DMA %i can not be halted\n", CIO2_DMA_CHAN);
>
>
--
Regards,
Laurent Pinchart
