iommu.lists.linux-foundation.org archive mirror
 help / color / mirror / Atom feed
From: Jon Hunter <jonathanh@nvidia.com>
To: Krishna Reddy <vdumpa@nvidia.com>
Cc: Sachin Nikam <Snikam@nvidia.com>,
	"nicoleotsuka@gmail.com" <nicoleotsuka@gmail.com>,
	Mikko Perttunen <mperttunen@nvidia.com>,
	Bryan Huntsman <bhuntsman@nvidia.com>,
	"will@kernel.org" <will@kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	Pritesh Raithatha <praithatha@nvidia.com>,
	Timo Alho <talho@nvidia.com>,
	"iommu@lists.linux-foundation.org"
	<iommu@lists.linux-foundation.org>,
	Nicolin Chen <nicolinc@nvidia.com>,
	"linux-tegra@vger.kernel.org" <linux-tegra@vger.kernel.org>,
	Yu-Huan Hsu <YHsu@nvidia.com>,
	Thierry Reding <treding@nvidia.com>,
	"robin.murphy@arm.com" <robin.murphy@arm.com>,
	"linux-arm-kernel@lists.infradead.org"
	<linux-arm-kernel@lists.infradead.org>,
	Bitan Biswas <bbiswas@nvidia.com>
Subject: Re: [PATCH v8 1/3] iommu/arm-smmu: add NVIDIA implementation for dual ARM MMU-500 usage
Date: Tue, 30 Jun 2020 17:32:41 +0100	[thread overview]
Message-ID: <4037efc7-fbed-e8cf-dac7-212c65014e4e@nvidia.com> (raw)
In-Reply-To: <BYAPR12MB282210677459B8D62623C642B36F0@BYAPR12MB2822.namprd12.prod.outlook.com>



On 30/06/2020 17:23, Krishna Reddy wrote:
>>> +struct arm_smmu_device *nvidia_smmu_impl_init(struct arm_smmu_device 
>>> +*smmu) {
>>> +	unsigned int i;
> ....
>>> +	for (i = 1; i < MAX_SMMU_INSTANCES; i++) {
>>> +		struct resource *res;
>>> +
>>> +		res = platform_get_resource(pdev, IORESOURCE_MEM, i);
>>> +		if (!res)
>>> +			break;
> 
>> Currently this driver is only supported for Tegra194 which I understand has 3 SMMUs. Therefore, I don't feel that we should fail silently here, I think it is better to return an error if all 3 cannot be initialised.
> 
> Initialization of all the three SMMU instances is not necessary here.

That is not what I am saying.

> The driver can work with all the possible number of instances 1, 2 and 3 based on the DT config though it doesn't make much sense to use it with 1 instance.
> There is no silent failure here from driver point of view. If there is misconfig in DT, SMMU faults would catch issues.

I disagree and you should return a proper error here.

>>> +		nvidia_smmu->bases[i] = devm_ioremap_resource(smmu->dev, res);
>>> +		if (IS_ERR(nvidia_smmu->bases[i]))
>>> +			return ERR_CAST(nvidia_smmu->bases[i]);
> 
>> You want to use PTR_ERR() here.
> 
> PTR_ERR() returns long integer. 
> This function returns a pointer. ERR_CAST is the right one to use here. 

Ah yes, indeed. OK that's fine.

Jon

-- 
nvpublic
_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu

  reply	other threads:[~2020-06-30 16:32 UTC|newest]

Thread overview: 38+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-06-30  0:10 [PATCH v8 0/3] Nvidia Arm SMMUv2 Implementation Krishna Reddy
2020-06-30  0:10 ` [PATCH v8 1/3] iommu/arm-smmu: add NVIDIA implementation for dual ARM MMU-500 usage Krishna Reddy
2020-06-30  0:16   ` Nicolin Chen
2020-06-30  5:54   ` Pritesh Raithatha
2020-06-30  8:19   ` Jon Hunter
2020-06-30 14:53     ` Robin Murphy
2020-06-30 15:17       ` Jon Hunter
2020-07-01 18:18       ` Krishna Reddy
2020-07-01 18:56         ` Robin Murphy
2020-07-01 19:12           ` Krishna Reddy
2020-06-30 17:04     ` Krishna Reddy
2020-06-30 10:17   ` Jon Hunter
2020-06-30 16:23     ` Krishna Reddy
2020-06-30 16:32       ` Jon Hunter [this message]
2020-06-30 16:44         ` Jon Hunter
2020-06-30 17:16           ` Krishna Reddy
2020-06-30 19:03             ` Jon Hunter
2020-06-30 20:21               ` Krishna Reddy
2020-06-30  0:10 ` [PATCH v8 2/3] dt-bindings: arm-smmu: Add binding for Tegra194 SMMU Krishna Reddy
2020-06-30  6:01   ` Pritesh Raithatha
2020-06-30  8:21   ` Jon Hunter
2020-06-30 12:27   ` Robin Murphy
2020-07-01 18:28     ` Krishna Reddy
2020-07-01 18:47       ` Jon Hunter
2020-07-01 19:00         ` Krishna Reddy
2020-07-01 19:31           ` Jon Hunter
2020-07-01 19:39             ` Krishna Reddy
2020-07-02 16:05               ` Robin Murphy
2020-07-01 19:03         ` Robin Murphy
2020-06-30  0:10 ` [PATCH v8 3/3] iommu/arm-smmu: Add global/context fault implementation hooks Krishna Reddy
2020-06-30  0:19   ` Nicolin Chen
2020-06-30  5:58   ` Pritesh Raithatha
2020-06-30  8:37   ` Jon Hunter
2020-06-30 12:13     ` Robin Murphy
2020-06-30 12:42       ` Jon Hunter
2020-07-01 18:48       ` Krishna Reddy
2020-07-01 19:14         ` Robin Murphy
2020-07-01 19:22           ` Krishna Reddy

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=4037efc7-fbed-e8cf-dac7-212c65014e4e@nvidia.com \
    --to=jonathanh@nvidia.com \
    --cc=Snikam@nvidia.com \
    --cc=YHsu@nvidia.com \
    --cc=bbiswas@nvidia.com \
    --cc=bhuntsman@nvidia.com \
    --cc=iommu@lists.linux-foundation.org \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-tegra@vger.kernel.org \
    --cc=mperttunen@nvidia.com \
    --cc=nicoleotsuka@gmail.com \
    --cc=nicolinc@nvidia.com \
    --cc=praithatha@nvidia.com \
    --cc=robin.murphy@arm.com \
    --cc=talho@nvidia.com \
    --cc=treding@nvidia.com \
    --cc=vdumpa@nvidia.com \
    --cc=will@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).