Messages in this thread | | | From | Phil Carmody <> | Subject | [RFC 0/6] Driver core: Encourage use of const attributes | Date | Thu, 17 Dec 2009 20:12:10 +0200 |
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I know now's probably a bad time to be mentioning const issues but I recently a reviewed a patch where 'const' was being removed from a device_attribute structure, and I enquired why. The reason was simply so that device_create_file() could be called, it taking a non-const attribute pointer. Looking inside, all that function did was pass a pointer to sysfs_create_file, which itself took a const pointer. Non-constness was not required at all.
So here I offer a small patchset which I hope will permit and encourage device and other attributes to be made const, and put in read-only sections.
1-3 address the three attribute types which seemed to be trivially const-able, and are the important part of the set.
4 adds a new macro to encourage the use of Const ATTRibutes, and may need a better name. (I wanted to avoid RO, for example.)
5 and 6 are merely two quick examples of how easy it is to adopt the new const convention. In reality, these structures have been constant and treated as constant by the driver core all along, it's just that one word was missing from a few important places.
I would hope to submit a patchset with 1-3 and a possibly modified 4. The migrations themselves will belong in different trees.
These have been compile/sparse tested against arm and x86_64 targets, and through my usual suite of tests on the arm platform I use.
Regards, Phil
Phil Carmody (6): Driver core: device_attribute parameters can often be const* Driver core: bin_attribute parameters can often be const* Driver core: driver_attribute parameters can often be const* Driver core: Easy macros to encourage const attributes PM: Example of how easy it is to mark attributes const gpio: Example of how easy it is to mark attributes const
drivers/base/core.c | 12 ++++++++---- drivers/base/driver.c | 4 ++-- drivers/gpio/gpiolib.c | 12 ++++++------ drivers/regulator/core.c | 38 +++++++++++++++++++------------------- fs/sysfs/bin.c | 6 ++++-- include/linux/device.h | 20 ++++++++++++++------ include/linux/sysfs.h | 9 +++++---- 7 files changed, 58 insertions(+), 43 deletions(-)
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