On Mon, 2021-10-25 at 12:03 +0800, Yong Wu wrote: > On Fri, 2021-10-22 at 16:03 +0200, Dafna Hirschfeld wrote: > > Hi > > > > > > On 23.09.21 13:58, Yong Wu wrote: > > > To simplify the code, Remove the power status checking in the > > > tlb_flush_all, remove this: > > > if (pm_runtime_get_if_in_use(data->dev) <= 0) > > > continue; > > > > > > After this patch, the mtk_iommu_tlb_flush_all will be called from > > > a) isr > > > b) pm runtime resume callback > > > c) tlb flush range fail case > > > d) iommu_create_device_direct_mappings > > > -> iommu_flush_iotlb_all > > > In first three cases, the power and clock always are enabled; d) > > > is > > > direct > > > > Regarding case "c) tlb flush range fail case", I found out that > > this > > often happens when the iommu is used while it is runtime > > suspended. > > Which SoC and branch are you testing on? > > > For example the mtk-vcodec encoder driver calls > > "pm_runtime_resume_and_get" only when it starts > > streaming but > > buffers allocation is done in 'v4l2_reqbufs' before > > "pm_runtime_resume_and_get" is called > > This is the case I tried to fix in [14/33]. > pm_runtime_get_if_in_use should return when the iommu device's pm is > not active when vcodec allocate buffer before pm_runtime_resume_and > get. > > Do you have the devicelink patchset in your branch? if not, the > vcodec > should call mtk_smi_larb_get to enable the power/clock for larbs, > then > the iommu's device is active via devicelink between smi and iommu > device. > > > and then I see the warning "Partial TLB flush timed out, falling > > back > > to full flush" > > I am not sure how to fix that issue, but it seems that case 'c)' Have your issue been fixed? or more information about it. Thanks. > > might indicate that > > power and clock are actually not enabled. > > > > > mapping, the tlb flush is unnecessay since we already have > > > tlb_flush_all > > > in the pm_runtime_resume callback. When the iommu's power status > > > is > > > changed to active, the tlb always is clean. > > > > > > In addition, there still are 2 reasons that don't add PM status > > > checking > > > in the tlb flush all: > > > a) Write tlb flush all register also is ok even though the HW has > > > no > > > power and clocks. Write ignore. > > > b) pm_runtime_get_if_in_use(m4udev) is 0 when the tlb_flush_all > > > is called frm pm_runtime_resume cb. From this point, we can not > > > add > > > this code above in this tlb_flush_all. > > > > > > Signed-off-by: Yong Wu <yong.wu@xxxxxxxxxxxx> > > > --- > > > drivers/iommu/mtk_iommu.c | 20 +++++++------------- > > > 1 file changed, 7 insertions(+), 13 deletions(-)
