Re: [PATCH] venus: core: add shutdown callback for venus

From: Sai Prakash Ranjan
Date: Wed Jun 24 2020 - 02:47:29 EST


Hi Mansur,

On 2020-06-13 16:03, Mansur Alisha Shaik wrote:
After the SMMU translation is disabled in the
arm-smmu shutdown callback during reboot, if
any subsystem are still alive then IOVAs they
are using will become PAs on bus, which may
lead to crash.

Below are the consumers of smmu from venus
arm-smmu: consumer: aa00000.video-codec supplier=15000000.iommu
arm-smmu: consumer: video-firmware.0 supplier=15000000.iommu

So implemented shutdown callback, which detach iommu maps.

Change-Id: I0f0f331056e0b84b92f1d86f66618d4b1caaa24a
Signed-off-by: Mansur Alisha Shaik <mansur@xxxxxxxxxxxxxx>
---
drivers/media/platform/qcom/venus/core.c | 9 +++++++++
1 file changed, 9 insertions(+)

diff --git a/drivers/media/platform/qcom/venus/core.c
b/drivers/media/platform/qcom/venus/core.c
index 30d4b9e..acf798c 100644
--- a/drivers/media/platform/qcom/venus/core.c
+++ b/drivers/media/platform/qcom/venus/core.c
@@ -371,6 +371,14 @@ static int venus_remove(struct platform_device *pdev)
return ret;
}

+static void venus_core_shutdown(struct platform_device *pdev)
+{
+ int ret;
+
+ ret = venus_remove(pdev);
+ WARN_ON(ret < 0);

I don't think you should warn here, its shutdown path and you can't
do anything with this WARN unlike remove callback where you have
to be sure to cleanup properly so that you are able to reload module.
But if you still want a hint about this failure, then just add a dev_err()
to indicate the failure instead of a big stack trace spamming kernel log.

Thanks,
Sai

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