Messages in this thread | | | Date | Thu, 29 Jan 2015 11:34:26 -0500 | From | Peter Hurley <> | Subject | Re: [PATCH v10 2/2] tty/serial: Add Spreadtrum sc9836-uart driver support |
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On 01/29/2015 11:05 AM, Russell King - ARM Linux wrote: > On Thu, Jan 29, 2015 at 10:49:34AM -0500, Peter Hurley wrote: >> Hi Varka, >> >> On 01/29/2015 10:26 AM, Varka Bhadram wrote: >>> This check is not required. It will be done by devm_ioremap_resource() >> >> I disagree. devm_ioremap_resource() interprets the NULL resource as >> a bad parameter and returns -EINVAL which is then forwarded as the >> return value from the probe. >> >> -ENODEV is the correct return value from the probe if the expected >> resource is not available (either because it doesn't exist or was already >> claimed by another driver). > > (Adding Thierry as the author of this function.) > > I believe devm_ioremap_resource() was explicitly designed to remove such > error handling from drivers, and to give drivers a unified error response > to such things as missing resources. > > See the comments for this function in lib/devres.c.
Maybe the purpose would be better served by wrapping the idiom in a single function.
Regards, Peter Hurley
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