On Sat, Sep 13, 2014 at 01:06:46AM +0200, Frans Klaver wrote:
> The disp attribute is write-only, but sysfs doesn't know this. Currently
> show_sys_acpi() is mimicking sysfs behavior, if the underlying acpi call
> should fail. This is not ideal; behaving like sysfs is better left to
> sysfs.
>
> Introduce EEEPC_CREATE_DEVICE_ATTR_WO() to instantiate a write-only
> attribute, and declare the disp attribute with it. Sysfs makes sure
> userspace can only write to disp at all times. This also means we can
> back to propagating any errors from get_acpi().
>
> Signed-off-by: Frans Klaver <franskla...@gmail.com>
> ---
> drivers/platform/x86/eeepc-laptop.c | 8 ++++++--
> 1 file changed, 6 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/platform/x86/eeepc-laptop.c
> b/drivers/platform/x86/eeepc-laptop.c
> index 3c04b77..4f6490d 100644
> --- a/drivers/platform/x86/eeepc-laptop.c
> +++ b/drivers/platform/x86/eeepc-laptop.c
> @@ -291,7 +291,7 @@ static ssize_t show_sys_acpi(struct device *dev, int cm,
> char *buf)
> int value = get_acpi(eeepc, cm);
>
> if (value < 0)
> - return -EIO;
> + return value;
> return sprintf(buf, "%d\n", value);
> }
>
> @@ -316,9 +316,13 @@ static ssize_t show_sys_acpi(struct device *dev, int cm,
> char *buf)
> EEEPC_ACPI_STORE_FUNC(_name, _cm) \
> static DEVICE_ATTR(_name, _mode, show_##_name, store_##_name)
>
> +#define EEEPC_CREATE_DEVICE_ATTR_WO(_name, _mode, _cm)
> \
> + EEEPC_ACPI_STORE_FUNC(_name, _cm) \
> + static DEVICE_ATTR(_name, _mode, NULL, store_##_name)
Per Greg's previous reply, I presume DEVICE_ATTR_WO here?
> +
> EEEPC_CREATE_DEVICE_ATTR(camera, S_IWUSR | S_IRUGO, CM_ASL_CAMERA);
> EEEPC_CREATE_DEVICE_ATTR(cardr, S_IWUSR | S_IRUGO, CM_ASL_CARDREADER);
> -EEEPC_CREATE_DEVICE_ATTR(disp, S_IWUSR, CM_ASL_DISPLAYSWITCH);
> +EEEPC_CREATE_DEVICE_ATTR_WO(disp, S_IWUSR, CM_ASL_DISPLAYSWITCH);
>
> struct eeepc_cpufv {
> int num;
> --
> 2.1.0
>
> --
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>
--
Darren Hart
Intel Open Source Technology Center
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