From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jan Glauber Subject: Re: [PATCH 5/5] mmc: cavium: Fix probing race with regulator Date: Tue, 16 May 2017 15:38:38 +0200 Message-ID: <20170516133838.GA20659@hc> References: <20170516093655.17746-1-jglauber@cavium.com> <20170516093655.17746-6-jglauber@cavium.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mail-sn1nam02on0088.outbound.protection.outlook.com ([104.47.36.88]:44913 "EHLO NAM02-SN1-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750757AbdEPNi4 (ORCPT ); Tue, 16 May 2017 09:38:56 -0400 Content-Disposition: inline In-Reply-To: Sender: linux-mmc-owner@vger.kernel.org List-Id: linux-mmc@vger.kernel.org To: Rob Herring Cc: Ulf Hansson , David Daney , Frank Rowand , "Steven J . Hill" , "linux-mmc@vger.kernel.org" , "linux-kernel@vger.kernel.org" On Tue, May 16, 2017 at 08:07:50AM -0500, Rob Herring wrote: > On Tue, May 16, 2017 at 4:36 AM, Jan Glauber wrote: > > If the regulator probing is not yet finished this driver > > might catch a -EPROBE_DEFER. Returning after this condition > > did not remove the created platform device. On a repeated > > call to the probe function the of_platform_device_create > > fails. > > > > Calling of_platform_device_destroy after EPROBE_DEFER resolves > > this bug. > > > > Signed-off-by: Jan Glauber > > --- > > drivers/mmc/host/cavium-thunderx.c | 4 +++- > > 1 file changed, 3 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/mmc/host/cavium-thunderx.c b/drivers/mmc/host/cavium-thunderx.c > > index fe3d772..257535e 100644 > > --- a/drivers/mmc/host/cavium-thunderx.c > > +++ b/drivers/mmc/host/cavium-thunderx.c > > @@ -137,8 +137,10 @@ static int thunder_mmc_probe(struct pci_dev *pdev, > > continue; > > > > ret = cvm_mmc_of_slot_probe(&host->slot_pdev[i]->dev, host); > > - if (ret) > > + if (ret) { > > + of_platform_device_destroy(&host->slot_pdev[i]->dev, NULL); > > What if this fails after the 1st iteration of the loop. It's only > cleaning up the current device. The platform device is just a dummy device created directly before cvm_mmc_of_slot_probe(). So there is no need to cleanup anything else. As far as I've seen it the platform code 'tags' the nodes it already used, but I need the same node to be parsed again on -EPROBE_DEFER. > Use devm_of_platform_populate or > of_platform_populate/of_platform_depopulate instead. I'm not sure one of these will work here. --Jan > Rob