From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Sat, 24 Mar 2018 10:04:46 +0100 From: Greg Kroah-Hartman To: Arend van Spriel Cc: LKML , Brian Norris Subject: Re: [PATCH for-4.16 2/3] drivers: change struct device_driver::coredump() return type to void Message-ID: <20180324090446.GA863@kroah.com> References: <1521107725-25027-1-git-send-email-aspriel@gmail.com> <1521107725-25027-3-git-send-email-aspriel@gmail.com> <20180323165543.GA21833@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.9.4 (2018-02-28) X-Mailing-List: linux-kernel@vger.kernel.org List-ID: On Sat, Mar 24, 2018 at 09:50:05AM +0100, Arend van Spriel wrote: > On Fri, Mar 23, 2018 at 5:55 PM, Greg Kroah-Hartman > wrote: > > On Thu, Mar 15, 2018 at 10:55:24AM +0100, Arend van Spriel wrote: > >> Upon submitting a patch for mwifiex [1] it was discussed whether this > >> callback function could fail. To keep things simple there is no need > >> for the error code so the driver can do the task synchronous or not > >> without worries. Currently the device driver core already ignores the > >> return value so changing it to void. > >> > >> [1] https://patchwork.kernel.org/patch/10231933/ > >> > >> Signed-off-by: Arend van Spriel > >> --- > >> include/linux/device.h | 5 ++++- > >> 1 file changed, 4 insertions(+), 1 deletion(-) > >> > >> diff --git a/include/linux/device.h b/include/linux/device.h > >> index b093405..f08c25b 100644 > >> --- a/include/linux/device.h > >> +++ b/include/linux/device.h > >> @@ -256,6 +256,9 @@ enum probe_type { > >> * automatically. > >> * @pm: Power management operations of the device which matched > >> * this driver. > >> + * @coredump: Called when sysfs entry is written to. The device driver > >> + * is expected to call the dev_coredump API resulting in a > >> + * uevent. > >> * @p: Driver core's private data, no one other than the driver > >> * core can touch this. > >> * > >> @@ -287,7 +290,7 @@ struct device_driver { > >> const struct attribute_group **groups; > >> > >> const struct dev_pm_ops *pm; > >> - int (*coredump) (struct device *dev); > >> + void (*coredump) (struct device *dev); > > > > Isn't this going to cause build warnings now? Are there no users of > > this callback function yet? > > Hi Greg, > > I submitted driver patches for the 4.17 kernel and from that > discussion we concluded it would be good to change to void return > type. So those driver patches were dropped. The caller of the callback > in drivers/base/dd.c does not use the return value so from that side > there is no issue. So my motivation for asking to consider this for > 4.16 is so I can resubmit the driver patches for 4.17 if there is > still time before the merge window. It's too late for 4.16 for this, and I would queue it up in my tree now but I don't want to cause any build warnings in linux-next from it. So how about I submit something like this right after 4.17-rc1 is out, where the function signature is changed _and_ all definitions of that function are changed at the same time to keep everything sane at once? Can you send me such a patch right before -rc1 is out base on Linus's tree? That should give everyone enough time to get the things merged, right? Or is there no in-flight patches to use this yet, and I can queue it up now for -rc1 as no build warnings will happen? thanks, greg k-h