From mboxrd@z Thu Jan 1 00:00:00 1970 From: Javier Martinez Canillas Subject: Re: [PATCH v2 1/2] ARM: OMAP2+: only search for GPMC DT child nodes on probe Date: Thu, 18 Apr 2013 11:05:46 +0200 Message-ID: <516FB76A.5080708@collabora.co.uk> References: <1366230852-2440-1-git-send-email-javier.martinez@collabora.co.uk> <516F13B8.20601@ti.com> <516F1DC8.2000707@collabora.co.uk> <516F2355.5080501@ti.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from bhuna.collabora.co.uk ([93.93.135.160]:38788 "EHLO bhuna.collabora.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755604Ab3DRJFt (ORCPT ); Thu, 18 Apr 2013 05:05:49 -0400 In-Reply-To: <516F2355.5080501@ti.com> Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: Jon Hunter Cc: Tony Lindgren , Enric Balletbo i Serra , Lars Poeschel , devicetree-discuss@lists.ozlabs.org, linux-omap On 04/18/2013 12:33 AM, Jon Hunter wrote: > > On 04/17/2013 05:10 PM, Javier Martinez Canillas wrote: >> On 04/17/2013 11:27 PM, Jon Hunter wrote: >>> >>> On 04/17/2013 03:34 PM, Javier Martinez Canillas wrote: >>>> The GPMC DT probe function use for_each_node_by_name() to search >>>> child device nodes of the GPMC controller. But this function does >>>> not use the GPMC device node as the root of the search and instead >>>> search across the complete Device Tree. >>>> >>>> This means that any device node on the DT that is using any of the >>>> GPMC child nodes names searched for will be returned even if they >>>> are not connected to the GPMC, making the gpmc_probe_xxx_child() >>>> function to fail. >>>> >>>> Fix this by using the GPMC device node as the search root so the >>>> search will be restricted to its children. >>>> >>>> Reported-by: Lars Poeschel >>>> Signed-off-by: Javier Martinez Canillas >>>> --- >>>> >>>> Changes since v1 (suggested by Jon Hunter): >>>> - Split the search for GPMC child nodes and only warn if a >>>> child probe fails on two different patches >>>> - Don't probe all childs unnecesary if a previous matched >>>> >>>> arch/arm/mach-omap2/gpmc.c | 33 ++++++++++----------------------- >>>> 1 files changed, 10 insertions(+), 23 deletions(-) >>>> >>>> diff --git a/arch/arm/mach-omap2/gpmc.c b/arch/arm/mach-omap2/gpmc.c >>>> index ed946df..6166847 100644 >>>> --- a/arch/arm/mach-omap2/gpmc.c >>>> +++ b/arch/arm/mach-omap2/gpmc.c >>>> @@ -1520,32 +1520,19 @@ static int gpmc_probe_dt(struct platform_device *pdev) >>>> return ret; >>>> } >>>> >>>> - for_each_node_by_name(child, "nand") { >>>> - ret = gpmc_probe_nand_child(pdev, child); >>>> - if (ret < 0) { >>>> - of_node_put(child); >>>> - return ret; >>>> - } >>>> - } >>>> + for_each_child_of_node(pdev->dev.of_node, child) { >>>> >>>> - for_each_node_by_name(child, "onenand") { >>>> - ret = gpmc_probe_onenand_child(pdev, child); >>>> - if (ret < 0) { >>>> - of_node_put(child); >>>> - return ret; >>>> - } >>>> - } >>>> + if (!child->name) >>>> + continue; >>>> >>>> - for_each_node_by_name(child, "nor") { >>>> - ret = gpmc_probe_generic_child(pdev, child); >>>> - if (ret < 0) { >>>> - of_node_put(child); >>>> - return ret; >>>> - } >>>> - } >>>> + if (of_node_cmp(child->name, "nand") == 0) >>>> + ret = gpmc_probe_nand_child(pdev, child); >>>> + else if (of_node_cmp(child->name, "onenand") == 0) >>>> + ret = gpmc_probe_onenand_child(pdev, child); >>>> + else if (of_node_cmp(child->name, "ethernet") == 0 || >>>> + of_node_cmp(child->name, "nor") == 0) >>>> + ret = gpmc_probe_generic_child(pdev, child); >>>> >>>> - for_each_node_by_name(child, "ethernet") { >>>> - ret = gpmc_probe_generic_child(pdev, child); >>>> if (ret < 0) { >>> >>> I think that we need to make sure that "ret" is initialised to 0 at the >>> beginning of the function. We should not have a case where the child >> >> Hi Jon, >> >> I didn't set ret to 0 at the beginning of the function since it is assigned the >> return value of a previous call to of_property_read_u32(). So ret should be 0 >> when execution reaches the for loop. > > Yes you are right, I overlooked that. > >>> name does not match but who knows. Actually that raises another point, >>> should we have an "else" clause at the end that WARNs on >>> "unknown/unsupported child" device? >>> >> >> Actually I thought about it when I was writing that patch and then I decided to >> not add a WARN for that case since nothing really fail in that case. >> >> I mean if we want to check that a DT is well formed then I think we will need to >> add much more checks and I don't know if is worth it. >> >> But I don't have a strong opinion on this so if you want I can add it an send a v3. > > Ok, that's fine. I am happy with this version, so no need then to re-do. > Great, thanks a lot for your feedback! Best regards, Javier