Re: [PATCH v3] spi: spi-fsl-qspi: Reduce devm_ioremap size to 4 times AHB buffer size

[Boris Brezillon <boris.brezillon@xxxxxxxxxxxxx>]

On Thu, 16 Apr 2020 17:13:19 +0530
Ashish Kumar <Ashish.Kumar@xxxxxxx> wrote:

> Reduce devm_ioremap size to (4 * AHB_BUFER_SIZE) rather than mapping
> complete QSPI-Memmory as driver is now independent of flash size.
> Flash of any size can be accessed.
> 
> Issue was reported on platform where devm_ioremap failure is observed
> with size > 256M.
> Error log on LS1021ATWR :
>  fsl-quadspi 1550000.spi: ioremap failed for resource [mem 0x40000000-0x7fffffff]
>  fsl-quadspi 1550000.spi: Freescale QuadSPI probe failed
>  fsl-quadspi: probe of 1550000.spi failed with error -12
> 
> This change was also suggested previously:
> https://patchwork.kernel.org/patch/10508753/#22166385
> 
> Suggested-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxx>
> Signed-off-by: Kuldeep Singh <kuldeep.singh@xxxxxxx>
> Signed-off-by: Ashish Kumar <Ashish.kumar@xxxxxxx>
> ---
> v3: 
> Update comment
> v2:
> Add Suggested-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxx>
> Incorrporate review comments from Frieder
>  drivers/spi/spi-fsl-qspi.c | 7 ++++---
>  1 file changed, 4 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/spi/spi-fsl-qspi.c b/drivers/spi/spi-fsl-qspi.c
> index 63c9f7e..8b95e2f 100644
> --- a/drivers/spi/spi-fsl-qspi.c
> +++ b/drivers/spi/spi-fsl-qspi.c
> @@ -859,14 +859,15 @@ static int fsl_qspi_probe(struct platform_device *pdev)
>  
>  	res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
>  					"QuadSPI-memory");
> -	q->ahb_addr = devm_ioremap_resource(dev, res);
> +	q->memmap_phy = res->start;
> +	/* Since there are 4 cs, map size required is 4 times ahb_buf_size */
> +	q->ahb_addr = devm_ioremap(dev, q->memmap_phy,
> +				   (q->devtype_data->ahb_buf_size * 4));
>  	if (IS_ERR(q->ahb_addr)) {
>  		ret = PTR_ERR(q->ahb_addr);
>  		goto err_put_ctrl;
>  	}
>  
> -	q->memmap_phy = res->start;
> -

Looks like this line move is unrelated to the ioremap range change. Not
a big but I thought I'd mention it. In any case,

Reviewed-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxx>

>  	/* find the clocks */
>  	q->clk_en = devm_clk_get(dev, "qspi_en");
>  	if (IS_ERR(q->clk_en)) {