Re: [PATCH 2/4] clk: tegra: check BPMP response return code

[Jon Hunter]

On 29/09/17 14:46, Timo Alho wrote:
> Hi Jon,
> 
> On 21.09.2017 14:21, Jonathan Hunter wrote:
>>
>>
>> On 07/09/17 10:31, Timo Alho wrote:
>>> Check return code in BPMP response message(s). The typical error case
>>> is when clock operation is attempted with invalid clock identifier.
>>>
>>> Also remove error print from call to clk_get_info() as the
>>> implementation loops through range of all possible identifier, but the
>>> operation is expected error out when the clock id is unused.
>>>
>>> Signed-off-by: Timo Alho <talho@xxxxxxxxxx>
>>> ---
>>> Â drivers/clk/tegra/clk-bpmp.c | 15 ++++++++++-----
>>> Â 1 file changed, 10 insertions(+), 5 deletions(-)
>>>
>>> diff --git a/drivers/clk/tegra/clk-bpmp.c b/drivers/clk/tegra/clk-bpmp.c
>>> index 638ace6..a896692 100644
>>> --- a/drivers/clk/tegra/clk-bpmp.c
>>> +++ b/drivers/clk/tegra/clk-bpmp.c
>>> @@ -55,6 +55,7 @@ struct tegra_bpmp_clk_message {
>>> ÂÂÂÂÂ struct {
>>> ÂÂÂÂÂÂÂÂÂ void *data;
>>> ÂÂÂÂÂÂÂÂÂ size_t size;
>>> +ÂÂÂÂÂÂÂ int ret;
>>> ÂÂÂÂÂ } rx;
>>> Â };
>>> Â @@ -64,6 +65,7 @@ static int tegra_bpmp_clk_transfer(struct
>>> tegra_bpmp *bpmp,
>>> ÂÂÂÂÂ struct mrq_clk_request request;
>>> ÂÂÂÂÂ struct tegra_bpmp_message msg;
>>> ÂÂÂÂÂ void *req = &request;
>>> +ÂÂÂ int err;
>>> Â ÂÂÂÂÂ memset(&request, 0, sizeof(request));
>>> ÂÂÂÂÂ request.cmd_and_id = (clk->cmd << 24) | clk->id;
>>> @@ -84,7 +86,13 @@ static int tegra_bpmp_clk_transfer(struct
>>> tegra_bpmp *bpmp,
>>> ÂÂÂÂÂ msg.rx.data = clk->rx.data;
>>> ÂÂÂÂÂ msg.rx.size = clk->rx.size;
>>> Â -ÂÂÂ return tegra_bpmp_transfer(bpmp, &msg);
>>> +ÂÂÂ err = tegra_bpmp_transfer(bpmp, &msg);
>>> +ÂÂÂ if (err < 0)
>>> +ÂÂÂÂÂÂÂ return err;
>>> +ÂÂÂ else if (msg.rx.ret < 0)
>>> +ÂÂÂÂÂÂÂ return -EINVAL;
>>
>> I assume that the error codes returned do not correlated to the Linux
>> error codes here. Is that correct? If not we could just return the
>> actual error code. Otherwise would it be useful to print a message with
>> the bpmp error code for debug?
> 
> The error codes are not 1:1 match with Linux. Unfortunately, printing
> message for debug is not either viable as during clock probing we are
> expecting many of the calls to return -BPMP_EINVAL to indicate that
> particular clock ID is unused.

OK. Could it return other errors other than BPMP_EINVAL? I am just
wondering if we need to differentiate between unused and an actual
error? Maybe that is not possible here?

Cheers
Jon

-- 
nvpublic