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

From: Suman Anna
Date: Thu May 18 2017 - 12:00:15 EST


Hi Sekhar,

On 05/18/2017 01:10 AM, Sekhar Nori wrote:
> 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 ?

Hmm, this trace is not just covering the dma_declare_contiguous failure.
There can be two different errors in da8xx_rproc_reserve_cma, and this
trace only shows up when the device is being registered. So not sure how
your suggestion improves anything by dropping/replacing one of them.

regards
Suman