linux-kernel - Re: [PATCH 1/3] iommu: of: Fix check for returning EPROBE_DEFER

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Message-ID: <1c306cf1-f7fb-87b1-1fef-3b08aea04560@codeaurora.org>
Date:   Thu, 18 May 2017 14:33:57 +0530
From:   Sricharan R <sricharan@...eaurora.org>
To:     Bjorn Helgaas <helgaas@...nel.org>
Cc:     robin.murphy@....com, will.deacon@....com, joro@...tes.org,
        lorenzo.pieralisi@....com, iommu@...ts.linux-foundation.org,
        linux-arm-kernel@...ts.infradead.org,
        linux-arm-msm@...r.kernel.org, m.szyprowski@...sung.com,
        bhelgaas@...gle.com, linux-pci@...r.kernel.org,
        linux-acpi@...r.kernel.org, tn@...ihalf.com, hanjun.guo@...aro.org,
        okaya@...eaurora.org, robh+dt@...nel.org, frowand.list@...il.com,
        devicetree@...r.kernel.org, linux-kernel@...r.kernel.org,
        sudeep.holla@....com, rjw@...ysocki.net, lenb@...nel.org,
        catalin.marinas@....com, arnd@...db.de, linux-arch@...r.kernel.org,
        magnus.damm@...il.com, geert@...ux-m68k.org, j.neuschaefer@....net
Subject: Re: [PATCH 1/3] iommu: of: Fix check for returning EPROBE_DEFER

Hi Bjorn,

On 5/17/2017 10:34 PM, Bjorn Helgaas wrote:
> On Wed, May 17, 2017 at 05:00:07PM +0530, Sricharan R wrote:
>> Now with iommu probe deferral, we return -EPROBE_DEFER
>> for master's that are connected to an iommu which is not
> 
> s/master's/masters/
> 
> s/iommu/IOMMU/ in your English text (changelogs and comments).  That seems
> to be the convention, based on "git log drivers/iommu/of_iommu.c"
> 

ok, will correct those.

Regards,
 Sricharan

>> probed yet, but going to get probed, so that we can attach
>> the correct dma_ops. So while trying to defer the probe of
>> the master, check if the of_iommu node that it is connected
>> to is marked in DT as 'status=disabled', then the iommu is never
>> is going to get probed. So simply return NULL and let the master
>> work without an iommu.
>>
>> Fixes: 7b07cbefb68d ("iommu: of: Handle IOMMU lookup failure with deferred probing or error")
>> Signed-off-by: Sricharan R <sricharan@...eaurora.org>
>> Reported-by: Geert Uytterhoeven <geert@...ux-m68k.org>
>> Tested-by: Will Deacon <will.deacon@....com>
>> Tested-by: Magnus Damn <magnus.damn@...il.com>
>> Acked-by: Will Deacon <will.deacon@....com>
>> ---
>>  drivers/iommu/of_iommu.c | 1 +
>>  1 file changed, 1 insertion(+)
>>
>> diff --git a/drivers/iommu/of_iommu.c b/drivers/iommu/of_iommu.c
>> index 9f44ee8..e6e9bec 100644
>> --- a/drivers/iommu/of_iommu.c
>> +++ b/drivers/iommu/of_iommu.c
>> @@ -118,6 +118,7 @@ static bool of_iommu_driver_present(struct device_node *np)
>>  
>>  	ops = iommu_ops_from_fwnode(fwnode);
>>  	if ((ops && !ops->of_xlate) ||
>> +	    !of_device_is_available(iommu_spec->np) ||
>>  	    (!ops && !of_iommu_driver_present(iommu_spec->np)))
>>  		return NULL;
>>  
>> -- 
>> QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation
>>
>>
>> _______________________________________________
>> linux-arm-kernel mailing list
>> linux-arm-kernel@...ts.infradead.org
>> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

-- 
"QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation

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