Re: [PATCH v1 6/7] media: ipu3-cio2: Use readl_poll_timeout() helper

[Bingbu Cao <bingbu.cao@linux.intel.com>]

On 8/15/20 12:30 AM, Andy Shevchenko wrote:
> We may use special helper macro to poll IO till condition or timeout occurs.
> 
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> ---
>  drivers/media/pci/intel/ipu3/ipu3-cio2.c | 17 ++++++++---------
>  1 file changed, 8 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/media/pci/intel/ipu3/ipu3-cio2.c b/drivers/media/pci/intel/ipu3/ipu3-cio2.c
> index f4175dc1501a..5f8ff91dbf09 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>
> @@ -509,7 +510,10 @@ 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 *dma = base + CIO2_REG_CDMAC0(CIO2_DMA_CHAN);
> +	unsigned int i;
> +	u32 value;
> +	int ret;
>  
>  	/* Disable CSI receiver and MIPI backend devices */
>  	writel(0, q->csi_rx_base + CIO2_REG_IRQCTRL_MASK);
> @@ -518,14 +522,9 @@ static void cio2_hw_exit(struct cio2_device *cio2, struct cio2_queue *q)
>  	writel(0, q->csi_rx_base + CIO2_REG_MIPIBE_ENABLE);
>  
>  	/* 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)
> +	writel(0, dma);
> +	ret = readl_poll_timeout(dma, value, value & CIO2_CDMAC0_DMA_HALTED, 4000, 2000000);

This line is too long, need a break, others look good for me.

> +	if (ret)
>  		dev_err(&cio2->pci_dev->dev,
>  			"DMA %i can not be halted\n", CIO2_DMA_CHAN);
>  
> 

-- 
Best regards,
Bingbu Cao