From mboxrd@z Thu Jan 1 00:00:00 1970 From: neilb@suse.de (NeilBrown) Date: Mon, 9 Mar 2015 11:06:53 +1100 Subject: twl4030_charger: need changes to get probed? In-Reply-To: <20150307210102.GL5233@earth> References: <20150224043341.4243.23291.stgit@notabene.brown> <20150224043352.4243.11227.stgit@notabene.brown> <20150302210926.GP13270@amd> <20150305173350.50502b95@notabene.brown> <20150306212417.GA24169@amd> <20150307210102.GL5233@earth> Message-ID: <20150309110653.7532613c@notabene.brown> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Sat, 7 Mar 2015 22:01:02 +0100 Sebastian Reichel wrote: > Hi, > > On Fri, Mar 06, 2015 at 10:24:17PM +0100, Pavel Machek wrote: > > According to n900 dts, twl4030-bci (aka charger) should be > > included. > > its part of twl, but not used on N900 afaik. > > > (But it does not seem to do anything useful on n900. I was hoping for > > measurement of input voltage, but .. no.) > > check for rx51-battery. > > > Any ideas why the patch below is needed? > > platform_driver_probe() does not support deferred probing. > > Neil, can you take this patch into your series for the next round? I could, but I do wonder if it is the right thing to do. Shouldn't we fix platform_driver_probe() to support deferred probing. As I understand it, it refused to retry a probe if there is an error, and the comments suggest that such retrying is avoided because it would be a waste of time: /* * Prevent driver from requesting probe deferral to avoid further * futile probe attempts. */ In this case, it isn't futile. Earlier there is a comment saying: * Use this instead of platform_driver_register() when you know the device * is not hotpluggable and has already been registered, and you want to * remove its run-once probe() infrastructure from memory after the driver * has bound to the device. I presume all this applies. I assume that the only problem is a probe-order thing. So maybe we should fix platform_driver_probe() to do the right thing with -EPROBEDEFER?? Trouble is, I really don't understand the point or mechanism for platform_driver_probe(), so I cannot suggest anything. But I have been annoyed before that platform_driver_probe doesn't cope with EPROBEDEFER, so I would like it fixed. NeilBrown -------------- next part -------------- A non-text attachment was scrubbed... Name: not available Type: application/pgp-signature Size: 811 bytes Desc: OpenPGP digital signature URL: