[permalink] [raw]

Subject: Re: [PATCH v10 02/13] iommu/mediatek-v1: Free the existed fwspec if the master dev already has

On 28/01/2022 13:45, Mauro Carvalho Chehab wrote:
> Em Fri, 28 Jan 2022 13:40:55 +0100
> Mauro Carvalho Chehab <[email protected]> escreveu:
>
>> Hi Matthias/Yong,
>>
>> Are you ok if this patch gets merged via the media tree together with the
>> remaining series, or do you prefer to apply it via SoC tree instead?
>
> Same questions for other patches touching files outside drivers/media
> on this pull request:
>
> https://patchwork.kernel.org/project/linux-mediatek/patch/[email protected]/
>

Looks good to me.

Please let me know once you accepted the pull request and I'll queue the DTS
related changes from this series.

Regards,
Matthias

> Like those:
> 0004-0013-iommu-mediatek-v1-Free-the-existed-fwspec-if-the-mas.patch
> 0005-0013-iommu-mediatek-Return-ENODEV-if-the-device-is-NULL.patch
> 0006-0013-iommu-mediatek-Add-probe_defer-for-smi-larb.patch
> 0007-0013-iommu-mediatek-Add-device_link-between-the-consumer-.patch
>
> Regards,
> Mauro
>
>>
>> Regards,
>> Mauro
>>
>>
>> Em Mon, 17 Jan 2022 15:04:59 +0800
>> Yong Wu <[email protected]> escreveu:
>>
>>> When the iommu master device enters of_iommu_xlate, the ops may be
>>> NULL(iommu dev is defered), then it will initialize the fwspec here:
>>>
>>> [<c0c9c5bc>] (dev_iommu_fwspec_set) from [<c06bda80>]
>>> (iommu_fwspec_init+0xbc/0xd4)
>>> [<c06bd9c4>] (iommu_fwspec_init) from [<c06c0db4>]
>>> (of_iommu_xlate+0x7c/0x12c)
>>> [<c06c0d38>] (of_iommu_xlate) from [<c06c10e8>]
>>> (of_iommu_configure+0x144/0x1e8)
>>>
>>> BUT the mtk_iommu_v1.c only supports arm32, the probing flow still is a bit
>>> weird. We always expect create the fwspec internally. otherwise it will
>>> enter here and return fail.
>>>
>>> static int mtk_iommu_create_mapping(struct device *dev,
>>> struct of_phandle_args *args)
>>> {
>>> ...
>>> if (!fwspec) {
>>> ....
>>> } else if (dev_iommu_fwspec_get(dev)->ops != &mtk_iommu_ops) {
>>> >>>>>>>>>>Enter here. return fail.<<<<<<<<<<<<
>>> return -EINVAL;
>>> }
>>> ...
>>> }
>>>
>>> Thus, Free the existed fwspec if the master device already has fwspec.
>>>
>>> This issue is reported at:
>>> https://lore.kernel.org/linux-mediatek/trinity-7d9ebdc9-4849-4d93-bfb5-429dcb4ee449-1626253158870@3c-app-gmx-bs01/
>>>
>>> Reported-by: Frank Wunderlich <[email protected]>
>>> Tested-by: Frank Wunderlich <[email protected]> # BPI-R2/MT7623
>>> Signed-off-by: Yong Wu <[email protected]>
>>> Acked-by: Joerg Roedel <[email protected]>
>>> Acked-by: AngeloGioacchino Del Regno <[email protected]>
>>> ---
>>> drivers/iommu/mtk_iommu_v1.c | 9 +++++++++
>>> 1 file changed, 9 insertions(+)
>>>
>>> diff --git a/drivers/iommu/mtk_iommu_v1.c b/drivers/iommu/mtk_iommu_v1.c
>>> index be22fcf988ce..1467ba1e4417 100644
>>> --- a/drivers/iommu/mtk_iommu_v1.c
>>> +++ b/drivers/iommu/mtk_iommu_v1.c
>>> @@ -425,6 +425,15 @@ static struct iommu_device *mtk_iommu_probe_device(struct device *dev)
>>> struct mtk_iommu_data *data;
>>> int err, idx = 0;
>>>
>>> + /*
>>> + * In the deferred case, free the existed fwspec.
>>> + * Always initialize the fwspec internally.
>>> + */
>>> + if (fwspec) {
>>> + iommu_fwspec_free(dev);
>>> + fwspec = dev_iommu_fwspec_get(dev);
>>> + }
>>> +
>>> while (!of_parse_phandle_with_args(dev->of_node, "iommus",
>>> "#iommu-cells",
>>> idx, &iommu_spec)) {
>>
>>
>>
>> Thanks,
>> Mauro
>
>
>
> Thanks,
> Mauro