Messages in this thread | | | Date | Wed, 4 Jun 2014 15:41:20 +0530 | Subject | Re: [PATCH v2 6/6] usb: host: ohci-exynos: Use devm_ioremap_resource instead of devm_ioremap | From | Vivek Gautam <> |
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Hi,
On Sat, May 10, 2014 at 5:30 PM, Vivek Gautam <gautam.vivek@samsung.com> wrote: > Using devm_ioremap_resource() API should actually be preferred over > devm_ioremap(), since the former request the mem region first and then > gives back the ioremap'ed memory pointer. > devm_ioremap_resource() calls request_mem_region(), therby preventing > other drivers to make any overlapping call to the same region. > > Signed-off-by: Vivek Gautam <gautam.vivek@samsung.com>
Although this patch and rest in the series are merged. But i have got a doubt, so making this thread alive.
> --- > drivers/usb/host/ohci-exynos.c | 7 +++---- > 1 file changed, 3 insertions(+), 4 deletions(-) > > diff --git a/drivers/usb/host/ohci-exynos.c b/drivers/usb/host/ohci-exynos.c > index 9cf80cb..dec691d 100644 > --- a/drivers/usb/host/ohci-exynos.c > +++ b/drivers/usb/host/ohci-exynos.c > @@ -120,10 +120,9 @@ skip_phy: > > hcd->rsrc_start = res->start; > hcd->rsrc_len = resource_size(res); > - hcd->regs = devm_ioremap(&pdev->dev, res->start, hcd->rsrc_len); > - if (!hcd->regs) { > - dev_err(&pdev->dev, "Failed to remap I/O memory\n"); > - err = -ENOMEM; > + hcd->regs = devm_ioremap_resource(&pdev->dev, res);
Here, we replaced devm_ioremap() call with devm_ioremap_resource(), which internally requests the memory region and then does a "devm_ioremap()" or "devm_ioremap_nocache()" based on the check for IORESOURCE_CACHEABLE flag.
But this flag is not set for the resource of this device. So should we be explicitly setting the flag in driver ?
The query goes for other patches too in this series, wherein devm_ioremap() call is replaced with devm_ioremap_resource().
[snip]
-- Best Regards Vivek Gautam Samsung R&D Institute, Bangalore India
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