On Mon, 2021-10-18 at 09:13 +0200, Dafna Hirschfeld wrote: > > On 16.10.21 04:23, Yong Wu wrote: > > On Mon, 2021-10-11 at 14:36 +0200, Dafna Hirschfeld wrote: > > > > > > On 29.09.21 03:37, Yong Wu wrote: > > > > MediaTek IOMMU-SMI diagram is like below. all the consumer > > > > connect > > > > with > > > > smi-larb, then connect with smi-common. > > > > > > > > M4U > > > > | > > > > smi-common > > > > | > > > > ------------- > > > > | | ... > > > > | | > > > > larb1 larb2 > > > > | | > > > > vdec venc > > > > > > > > When the consumer works, it should enable the smi-larb's power > > > > which > > > > also need enable the smi-common's power firstly. > > > > > > > > Thus, First of all, use the device link connect the consumer > > > > and > > > > the > > > > smi-larbs. then add device link between the smi-larb and smi- > > > > common. > > > > > > > > This patch adds device_link between the consumer and the larbs. > > > > > > > > When device_link_add, I add the flag DL_FLAG_STATELESS to avoid > > > > calling > > > > pm_runtime_xx to keep the original status of clocks. It can > > > > avoid > > > > two > > > > issues: > > > > 1) Display HW show fastlogo abnormally reported in [1]. At the > > > > beggining, > > > > all the clocks are enabled before entering kernel, but the > > > > clocks > > > > for > > > > display HW(always in larb0) will be gated after clk_enable and > > > > clk_disable > > > > called from device_link_add(->pm_runtime_resume) and rpm_idle. > > > > The > > > > clock > > > > operation happened before display driver probe. At that time, > > > > the > > > > display > > > > HW will be abnormal. > > > > > > > > 2) A deadlock issue reported in [2]. Use DL_FLAG_STATELESS to > > > > skip > > > > pm_runtime_xx to avoid the deadlock. > > > > > > > > Corresponding, DL_FLAG_AUTOREMOVE_CONSUMER can't be added, then > > > > device_link_removed should be added explicitly. > > > > > > > > [1] > > > > https://lore.kernel.org/linux-mediatek/1564213888.22908.4.camel@mhfsdcap03/ > > > > [2] https://lore.kernel.org/patchwork/patch/1086569/ > > > > > > > > Suggested-by: Tomasz Figa <tfiga@xxxxxxxxxxxx> > > > > Signed-off-by: Yong Wu <yong.wu@xxxxxxxxxxxx> > > > > Tested-by: Frank Wunderlich <frank-w@xxxxxxxxxxxxxxx> # BPI- > > > > R2/MT7623 > > > > --- > > > > drivers/iommu/mtk_iommu.c | 22 ++++++++++++++++++++++ > > > > drivers/iommu/mtk_iommu_v1.c | 20 +++++++++++++++++++- > > > > 2 files changed, 41 insertions(+), 1 deletion(-) > > > > > > > > diff --git a/drivers/iommu/mtk_iommu.c > > > > b/drivers/iommu/mtk_iommu.c > > > > index d5848f78a677..a2fa55899434 100644 > > > > --- a/drivers/iommu/mtk_iommu.c > > > > +++ b/drivers/iommu/mtk_iommu.c > > > > @@ -560,22 +560,44 @@ static struct iommu_device > > > > *mtk_iommu_probe_device(struct device *dev) > > > > { > > > > struct iommu_fwspec *fwspec = > > > > dev_iommu_fwspec_get(dev); > > > > struct mtk_iommu_data *data; > > > > + struct device_link *link; > > > > + struct device *larbdev; > > > > + unsigned int larbid; > > > > > > > > if (!fwspec || fwspec->ops != &mtk_iommu_ops) > > > > return ERR_PTR(-ENODEV); /* Not a iommu client > > > > device > > > > */ > > > > > > > > data = dev_iommu_priv_get(dev); > > > > > > > > + /* > > > > + * Link the consumer device with the smi-larb > > > > device(supplier) > > > > + * The device in each a larb is a independent HW. thus > > > > only > > > > link > > > > + * one larb here. > > > > + */ > > > > + larbid = MTK_M4U_TO_LARB(fwspec->ids[0]); > > > > > > so larbid is always the same for all the ids of a device? > > > > Yes. For me, each a dtsi node should represent a HW unit which can > > only > > connect one larb. > > > > > If so maybe it worth testing it and return error if this is not > > > the > > > case. > > > > Thanks for the suggestion. This is very helpful. I did see someone > > put > > the different larbs in one node. I will check this, and add return > > I am working on bugs found on media drivers, could you please point > me to > that wrong node? > Will you send a fix to that node in the dtsi? sorry. I mean it happened in the internal branch and it has already been fixed internally, all the upstream nodes are ok for this. Thanks > > > Thanks, > Dafna > > > EINVAL for this case. > > > > > > > > > > > Thanks, > > > Dafna > > > > > > > >
