From: "Yong Wu (吴勇)" <Yong.Wu@mediatek.com>
To: "hsinyi@chromium.org" <hsinyi@chromium.org>
Cc: "linux-mediatek@lists.infradead.org"
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Subject: Re: [PATCH v2 11/29] iommu/mediatek: Always pm_runtime_get while tlb flush
Date: Wed, 1 Sep 2021 12:10:39 +0000 [thread overview]
Message-ID: <e3d8139174e659c07a606122d4a5402ee5e8adca.camel@mediatek.com> (raw)
In-Reply-To: <CAJMQK-hkufqh2vaEKcuO+k0v2SzpCHcyZuEqrvJ__rrAek2P0A@mail.gmail.com>
On Tue, 2021-08-24 at 15:10 +0800, Hsin-Yi Wang wrote:
> On Fri, Aug 13, 2021 at 2:57 PM Yong Wu <yong.wu@mediatek.com> wrote:
> >
> > Prepare for 2 HWs that sharing pgtable in different power-domains.
> >
> > The previous SoC don't have PM. Only mt8192 has power-domain,
> > and it is display's power-domain which nearly always is enabled.
> >
> > When there are 2 M4U HWs, it may has problem.
> > In this function, we get the pm_status via the m4u dev, but it
> > don't
> > reflect the real power-domain status of the HW since there may be
> > other
> > HW also use that power-domain.
> >
> > Currently we could not get the real power-domain status, thus
> > always
> > pm_runtime_get here.
> >
> > Prepare for mt8195, thus, no need fix tags here.
> >
> > This patch may drop the performance, we expect the user could
> > pm_runtime_get_sync before dma_alloc_attrs which need tlb ops.
>
> Can you check if there are existing users that need to add this
> change?
The issue may exist in our most users. Our users mainly are in v4l2.
normally their flow like this:
a) VIDIOC_REQBUFS: call dma_alloc_attrs or dma_buf_map_attachment.
b) VIDIOC_STREAMON.
c) VIDIOC_QBUF: device_run: pm_runtime_get_sync.
Requesting they call pm_runtime_get before dma_alloc_attrs looks not
reasonable. It seems that they should not care about this.
This patch mainly make sure the flow is right. Locally I have a TODO to
try get the real power-domain status here, the sample code like below:
static struct notifier_block mtk_penpd_notifier;
/* Register the genpd notifier. */
mtk_penpd_notifier.notifier_call = mtk_iommu_pd_callback;
ret = dev_pm_genpd_add_notifier(dev, &mtk_penpd_notifier);
/* Then get the real power domain status in the notifier */
static int mtk_iommu_pd_callback(struct notifier_block *nb,
unsigned long flags, void *data)
{
if (flags == GENPD_NOTIFY_ON)
/* the real power domain is power on */
else if (flags == GENPD_NOTIFY_PRE_OFF)
/* the real power domain are going to power off. Take it as
power off.
* Skip the tlb ops after receivice this flag.
*/
}
How about this? or any other suggestion to get the real power-domain
rather than the iommu device's power domain status.
Thanks.
>
>
> >
> > Signed-off-by: Yong Wu <yong.wu@mediatek.com>
> > ---
>
> <snip>
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next prev parent reply other threads:[~2021-09-01 13:44 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-13 6:52 [PATCH v2 00/29] MT8195 IOMMU SUPPORT Yong Wu
2021-08-13 6:52 ` [PATCH v2 01/29] dt-bindings: mediatek: mt8195: Add binding for MM IOMMU Yong Wu
2021-08-13 6:52 ` [PATCH v2 02/29] dt-bindings: mediatek: mt8195: Add binding for infra IOMMU Yong Wu
2021-08-17 21:44 ` Rob Herring
2021-08-13 6:52 ` [PATCH v2 03/29] iommu/mediatek: Fix 2 HW sharing pgtable issue Yong Wu
2021-08-13 6:52 ` [PATCH v2 04/29] iommu/mediatek: Adapt sharing and non-sharing pgtable case Yong Wu
2021-08-13 6:53 ` [PATCH v2 05/29] iommu/mediatek: Add 12G~16G support for multi domains Yong Wu
2021-08-13 6:53 ` [PATCH v2 06/29] iommu/mediatek: Add a flag DCM_DISABLE Yong Wu
2021-08-13 6:53 ` [PATCH v2 07/29] iommu/mediatek: Add a flag NON_STD_AXI Yong Wu
2021-08-13 6:53 ` [PATCH v2 08/29] iommu/mediatek: Remove for_each_m4u in tlb_sync_all Yong Wu
2021-08-13 6:53 ` [PATCH v2 09/29] iommu/mediatek: Add tlb_lock in tlb_flush_all Yong Wu
2021-08-13 6:53 ` [PATCH v2 10/29] iommu/mediatek: Remove the granule in the tlb flush Yong Wu
2021-08-13 6:53 ` [PATCH v2 11/29] iommu/mediatek: Always pm_runtime_get while " Yong Wu
2021-08-24 7:10 ` Hsin-Yi Wang
2021-09-01 12:10 ` Yong Wu (吴勇) [this message]
2021-09-30 11:26 ` Dafna Hirschfeld
2021-10-07 3:00 ` Yong Wu
2021-08-13 6:53 ` [PATCH v2 12/29] iommu/mediatek: Always enable output PA over 32bits in isr Yong Wu
2021-08-13 6:53 ` [PATCH v2 13/29] iommu/mediatek: Add SUB_COMMON_3BITS flag Yong Wu
2021-08-13 6:53 ` [PATCH v2 14/29] iommu/mediatek: Add IOMMU_TYPE flag Yong Wu
2021-08-13 6:53 ` [PATCH v2 15/29] iommu/mediatek: Contain MM IOMMU flow with the MM TYPE Yong Wu
2021-08-13 6:53 ` [PATCH v2 16/29] iommu/mediatek: Adjust device link when it is sub-common Yong Wu
2021-08-24 7:35 ` Hsin-Yi Wang
2021-09-01 12:01 ` Yong Wu (吴勇)
2021-08-13 6:53 ` [PATCH v2 17/29] iommu/mediatek: Add infra iommu support Yong Wu
2021-08-13 6:53 ` [PATCH v2 18/29] iommu/mediatek: Add PCIe support Yong Wu
2021-08-13 6:53 ` [PATCH v2 19/29] iommu/mediatek: Add mt8195 support Yong Wu
2021-08-13 6:53 ` [PATCH v2 20/29] iommu/mediatek: Only adjust code about register base Yong Wu
2021-08-13 6:53 ` [PATCH v2 21/29] iommu/mediatek: Just move code position in hw_init Yong Wu
2021-08-13 6:53 ` [PATCH v2 22/29] iommu/mediatek: Add mtk_iommu_bank_data structure Yong Wu
2021-08-13 6:53 ` [PATCH v2 23/29] iommu/mediatek: Initialise bank HW for each a bank Yong Wu
2021-08-13 6:53 ` [PATCH v2 24/29] iommu/mediatek: Add bank_nr and bank_enable Yong Wu
2021-08-13 6:53 ` [PATCH v2 25/29] iommu/mediatek: Change the domid to iova_region_id Yong Wu
2021-08-13 6:53 ` [PATCH v2 26/29] iommu/mediatek: Get the proper bankid for multi banks Yong Wu
2021-08-13 6:53 ` [PATCH v2 27/29] iommu/mediatek: Initialise/Remove for multi bank dev Yong Wu
2021-08-13 6:53 ` [PATCH v2 28/29] iommu/mediatek: Backup/restore regsiters for multi banks Yong Wu
2021-08-13 6:53 ` [PATCH v2 29/29] iommu/mediatek: mt8195: Enable multi banks for infra iommu Yong Wu
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