Hi,

On 8/7/20 9:24 AM, Mansur Alisha Shaik wrote:
> In concurrency usecase and reboot scenario we are trying
> to map fw.iommu_domain which is already unmapped during

I guess you want to say "to unmap iommu domain which is already unmapped" ?

> shutdown. This is causing NULL pointer dereference crash.
> 
> This case is handled by adding necessary checks.
> 
> Call trace:
>  __iommu_map+0x4c/0x348
>  iommu_map+0x5c/0x70
>  venus_boot+0x184/0x230 [venus_core]
>  venus_sys_error_handler+0xa0/0x14c [venus_core]
>  process_one_work+0x210/0x3d0
>  worker_thread+0x248/0x3f4
>  kthread+0x11c/0x12c
>  ret_from_fork+0x10/0x18
> 
> Signed-off-by: Mansur Alisha Shaik <man...@codeaurora.org>
> ---
>  drivers/media/platform/qcom/venus/firmware.c | 17 +++++++++++++----
>  1 file changed, 13 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/media/platform/qcom/venus/firmware.c 
> b/drivers/media/platform/qcom/venus/firmware.c
> index 8801a6a..c427e88 100644
> --- a/drivers/media/platform/qcom/venus/firmware.c
> +++ b/drivers/media/platform/qcom/venus/firmware.c
> @@ -171,9 +171,14 @@ static int venus_shutdown_no_tz(struct venus_core *core)
>  
>       iommu = core->fw.iommu_domain;
>  
> -     unmapped = iommu_unmap(iommu, VENUS_FW_START_ADDR, mapped);
> -     if (unmapped != mapped)
> -             dev_err(dev, "failed to unmap firmware\n");
> +     if (core->fw.mapped_mem_size && iommu) {
> +             unmapped = iommu_unmap(iommu, VENUS_FW_START_ADDR, mapped);
> +
> +             if (unmapped != mapped)
> +                     dev_err(dev, "failed to unmap firmware\n");
> +             else
> +                     core->fw.mapped_mem_size = 0;
> +     }
>  
>       return 0;
>  }
> @@ -288,7 +293,11 @@ void venus_firmware_deinit(struct venus_core *core)
>       iommu = core->fw.iommu_domain;
>  
>       iommu_detach_device(iommu, core->fw.dev);
> -     iommu_domain_free(iommu);
> +
> +     if (core->fw.iommu_domain) {
> +             iommu_domain_free(iommu);
> +             core->fw.iommu_domain = NULL;
> +     }
>  
>       platform_device_unregister(to_platform_device(core->fw.dev));
>  }
> 

-- 
regards,
Stan

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