Re: [PATCH 08/28] venus: hfi_venus: add suspend function for 4xx version

[Stanimir Varbanov]

Hi Vikash,

On 05/02/2018 09:07 AM, vgarodia@xxxxxxxxxxxxxx wrote:
> Hello Stanimir,
> 
> On 2018-04-24 18:14, Stanimir Varbanov wrote:
>> This adds suspend (power collapse) function with slightly
>> different order of calls comparing with Venus 3xx.
>>
>> Signed-off-by: Stanimir Varbanov <stanimir.varbanov@xxxxxxxxxx>
>> ---
>> Âdrivers/media/platform/qcom/venus/hfi_venus.c | 52
>> +++++++++++++++++++++++++++
>> Â1 file changed, 52 insertions(+)
>>
>> diff --git a/drivers/media/platform/qcom/venus/hfi_venus.c
>> b/drivers/media/platform/qcom/venus/hfi_venus.c
>> index 53546174aab8..f61d34bf61b4 100644
>> --- a/drivers/media/platform/qcom/venus/hfi_venus.c
>> +++ b/drivers/media/platform/qcom/venus/hfi_venus.c
>> @@ -1443,6 +1443,55 @@ static int venus_suspend_1xx(struct venus_core
>> *core)
>> ÂÂÂÂ return 0;
>> Â}
>>
>> +static int venus_suspend_4xx(struct venus_core *core)
>> +{
>> +ÂÂÂ struct venus_hfi_device *hdev = to_hfi_priv(core);
>> +ÂÂÂ struct device *dev = core->dev;
>> +ÂÂÂ u32 val;
>> +ÂÂÂ int ret;
>> +
>> +ÂÂÂ if (!hdev->power_enabled || hdev->suspended)
>> +ÂÂÂÂÂÂÂ return 0;
>> +
>> +ÂÂÂ mutex_lock(&hdev->lock);
>> +ÂÂÂ ret = venus_is_valid_state(hdev);
>> +ÂÂÂ mutex_unlock(&hdev->lock);
>> +
>> +ÂÂÂ if (!ret) {
>> +ÂÂÂÂÂÂÂ dev_err(dev, "bad state, cannot suspend\n");
>> +ÂÂÂÂÂÂÂ return -EINVAL;
>> +ÂÂÂ }
>> +
>> +ÂÂÂ ret = venus_prepare_power_collapse(hdev, false);
>> +ÂÂÂ if (ret) {
>> +ÂÂÂÂÂÂÂ dev_err(dev, "prepare for power collapse fail (%d)\n", ret);
>> +ÂÂÂÂÂÂÂ return ret;
>> +ÂÂÂ }
>> +
>> +ÂÂÂ ret = readl_poll_timeout(core->base + CPU_CS_SCIACMDARG0, val,
>> +ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ val & CPU_CS_SCIACMDARG0_PC_READY,
>> +ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ POLL_INTERVAL_US, 100000);
>> +ÂÂÂ if (ret) {
>> +ÂÂÂÂÂÂÂ dev_err(dev, "Polling power collapse ready timed out\n");
>> +ÂÂÂÂÂÂÂ return ret;
>> +ÂÂÂ }
>> +
>> +ÂÂÂ mutex_lock(&hdev->lock);
>> +
>> +ÂÂÂ ret = venus_power_off(hdev);
>> +ÂÂÂ if (ret) {
>> +ÂÂÂÂÂÂÂ dev_err(dev, "venus_power_off (%d)\n", ret);
>> +ÂÂÂÂÂÂÂ mutex_unlock(&hdev->lock);
>> +ÂÂÂÂÂÂÂ return ret;
>> +ÂÂÂ }
>> +
>> +ÂÂÂ hdev->suspended = true;
>> +
>> +ÂÂÂ mutex_unlock(&hdev->lock);
>> +
>> +ÂÂÂ return 0;
>> +}
>> +
>> Âstatic int venus_suspend_3xx(struct venus_core *core)
>> Â{
>> ÂÂÂÂ struct venus_hfi_device *hdev = to_hfi_priv(core);
>> @@ -1507,6 +1556,9 @@ static int venus_suspend(struct venus_core *core)
>> ÂÂÂÂ if (core->res->hfi_version == HFI_VERSION_3XX)
>> ÂÂÂÂÂÂÂÂ return venus_suspend_3xx(core);
>>
>> +ÂÂÂ if (core->res->hfi_version == HFI_VERSION_4XX)
>> +ÂÂÂÂÂÂÂ return venus_suspend_4xx(core);
>> +
>> ÂÂÂÂ return venus_suspend_1xx(core);
>> Â}
> 
> Let me brief on the power collapse sequence for Venus_4xx
> 1. Host checks for ARM9 and Video core to be idle.
> ÂÂ This can be done by checking for WFI bit (bit 0) in CPU status
> register for ARM9 and by checking bit 30 in Control status reg for video
> core/s.
> 2. Host then sends command to ARM9 to prepare for power collapse.
> 3. Host then checks for WFI bit and PC_READY bit before withdrawing
> going for power off.
> 
> As per this patch, host is preparing for power collapse without checking
> for #1.
> Update the code to handle #3.

This looks similar to suspend for Venus 3xx. Can you confirm that the
sequence of checks for 4xx is the same as 3xx?

-- 
regards,
Stan