Re: [PATCH 1/3] ARM: davinci: da8xx: Create DSP device only when assigned memory

From: Sekhar Nori
Date: Thu May 18 2017 - 02:11:34 EST


On Wednesday 17 May 2017 03:43 AM, Suman Anna wrote:
> The DSP device on Davinci platforms does not have an MMU and requires
> specific DDR memory to boot. This memory is reserved using the rproc_mem
> kernel boot parameter and is assigned to the device on non-DT boots.
> The remoteproc core uses the DMA API and so will fall back to assigning
> random memory if this memory is not assigned to the device, but the DSP
> remote processor boot will not be successful in such cases. So, check
> that memory has been reserved and assigned to the device specifically
> before even creating the DSP device.
>
> Signed-off-by: Suman Anna <s-anna@xxxxxx>
> ---
> arch/arm/mach-davinci/devices-da8xx.c | 10 ++++++++++
> 1 file changed, 10 insertions(+)
>
> diff --git a/arch/arm/mach-davinci/devices-da8xx.c b/arch/arm/mach-davinci/devices-da8xx.c
> index 7cf529ffbe5a..1ccf52e49886 100644
> --- a/arch/arm/mach-davinci/devices-da8xx.c
> +++ b/arch/arm/mach-davinci/devices-da8xx.c
> @@ -814,6 +814,8 @@ static struct platform_device da8xx_dsp = {
> .resource = da8xx_rproc_resources,
> };
>
> +static bool rproc_mem_inited __initdata;
> +
> #if IS_ENABLED(CONFIG_DA8XX_REMOTEPROC)
>
> static phys_addr_t rproc_base __initdata;
> @@ -852,6 +854,8 @@ void __init da8xx_rproc_reserve_cma(void)
> ret = dma_declare_contiguous(&da8xx_dsp.dev, rproc_size, rproc_base, 0);
> if (ret)
> pr_err("%s: dma_declare_contiguous failed %d\n", __func__, ret);
> + else
> + rproc_mem_inited = true;
> }
>
> #else
> @@ -866,6 +870,12 @@ int __init da8xx_register_rproc(void)
> {
> int ret;
>
> + if (!rproc_mem_inited) {
> + pr_warn("%s: memory not reserved for DSP, not registering DSP device\n",
> + __func__);

We now have a warning and an error if dma_declare_contiguous() fails. I
like this message better. So can you replace the existing error message
with this text instead ?

Thanks,
Sekhar