From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 374FAC2D0A3 for ; Mon, 9 Nov 2020 12:04:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D29E020789 for ; Mon, 9 Nov 2020 12:04:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1604923456; bh=NLvzFe8LX2GurxJBTWk/+gN/PMnYyodXLMzk/dJFOq4=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=2aPjJU3kj4jm5f4+TEyzHJKMgqL5DTUkeTsnyxExG5SmXklnmP65jPVYSIM5zoXhf fhSQQpXX57wiWFHSFd7dG/Jc1+vb9yE6jQ0h3Mfb4r5zkpTzXSv5rFUCloOmICRV+R F3GUn22jplhAiytHqbVIrLVS7lCByZz91BYx9490= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729537AbgKIMEP (ORCPT ); Mon, 9 Nov 2020 07:04:15 -0500 Received: from mail.kernel.org ([198.145.29.99]:39146 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726410AbgKIMEP (ORCPT ); Mon, 9 Nov 2020 07:04:15 -0500 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 8893A20789; Mon, 9 Nov 2020 12:04:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1604923453; bh=NLvzFe8LX2GurxJBTWk/+gN/PMnYyodXLMzk/dJFOq4=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=m0Yx8nVdJUfbIc5xXr5eyYCCHWMIj+k3v5Cv0QRODAwl6Wd7/9/tyz8wmCAq0HjwG 1n0y7oD2r/uIOqxveBOJvaZhN9D6T8mdypt4panNLD5zWf/o3AQiDKAH3Md5wO9gwr aJRFULWTKvF6IkkjIMGoE/uf6v44LIm28eLL5Xj0= Date: Mon, 9 Nov 2020 13:05:12 +0100 From: Greg Kroah-Hartman To: Aisheng Dong Cc: Sudip Mukherjee , "Rafael J . Wysocki" , linux-kernel , Shawn Guo , Stephen Boyd Subject: Re: [PATCH RESEND] driver core: export device_is_bound() to fix build failure Message-ID: <20201109120512.GB1832201@kroah.com> References: <20201107224727.11015-1-sudipm.mukherjee@gmail.com> <20201108082317.GA40741@kroah.com> <20201109103703.GA1310551@kroah.com> <20201109114125.GC1769924@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Nov 09, 2020 at 11:55:46AM +0000, Aisheng Dong wrote: > > From: Greg Kroah-Hartman > > Sent: Monday, November 9, 2020 7:41 PM > > > > On Mon, Nov 09, 2020 at 10:57:05AM +0000, Aisheng Dong wrote: > > > Hi Greg, > > > > > > > From: Greg Kroah-Hartman > > > > Sent: Monday, November 9, 2020 6:37 PM > > > > Subject: Re: [PATCH RESEND] driver core: export device_is_bound() to > > > > fix build failure > > > > > > > > On Mon, Nov 09, 2020 at 10:14:46AM +0000, Sudip Mukherjee wrote: > > > > > Hi Greg, > > > > > > > > > > On Sun, Nov 8, 2020 at 8:23 AM Greg Kroah-Hartman > > > > > wrote: > > > > > > > > > > > > On Sat, Nov 07, 2020 at 10:47:27PM +0000, Sudip Mukherjee wrote: > > > > > > > When CONFIG_MXC_CLK_SCU is configured as 'm' the build fails > > > > > > > as it is unable to find device_is_bound(). The error being: > > > > > > > ERROR: modpost: "device_is_bound" [drivers/clk/imx/clk-imx-scu.ko] > > > > > > > undefined! > > > > > > > > > > > > > > Export the symbol so that the module finds it. > > > > > > > > > > > > > > Fixes: 77d8f3068c63 ("clk: imx: scu: add two cells binding > > > > > > > support") > > > > > > > Signed-off-by: Sudip Mukherjee > > > > > > > --- > > > > > > > > > > > > > > resending with the Fixes: tag. > > > > > > > > > > > > > > drivers/base/dd.c | 1 + > > > > > > > 1 file changed, 1 insertion(+) > > > > > > > > > > > > > > diff --git a/drivers/base/dd.c b/drivers/base/dd.c index > > > > > > > 148e81969e04..a796a57e5efb 100644 > > > > > > > --- a/drivers/base/dd.c > > > > > > > +++ b/drivers/base/dd.c > > > > > > > @@ -353,6 +353,7 @@ bool device_is_bound(struct device *dev) { > > > > > > > return dev->p && > > > > > > > klist_node_attached(&dev->p->knode_driver); > > > > > > > } > > > > > > > +EXPORT_SYMBOL(device_is_bound); > > > > > > > > > > > > EXPORT_SYMBOL_GPL() please, like all the other exports in this file. > > > > > > > > > > > > Also, wait, no, don't call this, are you sure you are calling it > > > > > > in a race-free way? And what branch/tree is the above commit in? > > > > > > > > > > I have not checked fully but since it is being called from probe() > > > > > I assume the lock will be held at that time. > > > > > > > > probe() should never call this function as it makes no sense at all > > > > at that point in time. The driver should be fixed. > > > > > > Would you suggest if any other API we can use to allow the driver to > > > know whether another device has been probed? > > > > There is none, sorry, as that just opens up way too many problems. > > > > > For imx scu driver in question, it has a special requirement that it > > > depends on scu power domain driver. However, there're a huge number > > > (200+) of power domains for each device clock, we can't define them all in DT > > for a single clock controller node. > > > > > > That's why we wanted to use device_is_bound() before to check if scu > > > power domain is ready or not to support defer probe. > > > > Use the device link functionality for this type of thing, that is what it was created > > for. > > > > Thanks for the suggestion. I will check it how to use. > BTW, I wonder if dev_driver_string() could be an optional solution which seems a more > simple way? Also, how do you really know you even have a valid pointer to that other device structure? How are you getting access to that? thanks, greg k-h