Re: [PATCH] regulator: qcom-rpmh: Revert "regulator: qcom-rpmh: Use PROBE_FORCE_SYNCHRONOUS"

[Caleb Connolly]

On 13/05/2023 18:08, Amit Pundir wrote:
> On Fri, 24 Mar 2023 at 19:05, Douglas Anderson <dianders@xxxxxxxxxxxx> wrote:
>>
>> This reverts commit 58973046c1bf ("regulator: qcom-rpmh: Use
>> PROBE_FORCE_SYNCHRONOUS"). Further digging into the problems that
>> prompted the us to switch to synchronous probe showed that the root
>> cause was a missing "rootwait" in the kernel command line
>> arguments. Let's reinstate asynchronous probe.
> 
> Hi, the asynchronous probe is broken on Dragonboard 845c (SDM845)
> running AOSP (Android Open Source Project) with v6.4-rc1
> https://bugs.linaro.org/show_bug.cgi?id=5975.
> Can we please go back to synchronous probe.
> 
> AOSP do not make use of rootwait, IIRC, but it is added by the
> bootloader anyway. And the device fails to boot AOSP regardless of
> "rootwait" bootarg being present or not.

Could you try applying this diff to enable some log spam and let me know
what you get? I'm keen to try and figure this one out. My mail client
might crunch this a bit so I have pasted it here too
https://p.calebs.dev/ab74b7@raw

diff --git a/drivers/soc/qcom/rpmh-rsc.c b/drivers/soc/qcom/rpmh-rsc.c
index f93544f6d796..67859f1bdb28 100644
--- a/drivers/soc/qcom/rpmh-rsc.c
+++ b/drivers/soc/qcom/rpmh-rsc.c
@@ -653,11 +653,23 @@ int rpmh_rsc_send_data(struct rsc_drv *drv, const
struct tcs_request *msg)

        spin_lock_irqsave(&drv->lock, flags);

+       dev_info(drv->dev, "%s: %p tcs->type=%d state=%d, "
+               "wait_for_compl=%d, num_cmds=%d\n",
+               __func__, msg, tcs->type, msg->state,
+               msg->wait_for_compl, msg->num_cmds);
+       for (int i = 0; i < msg->num_cmds; i++)
+               dev_info(drv->dev, "%s: %p cmd[%d] "
+                       "addr=0x%x data=0x%x\n", __func__,
+                       msg, i, msg->cmds[i].addr, msg->cmds[i].data);
+
        /* Wait forever for a free tcs. It better be there eventually! */
        wait_event_lock_irq(drv->tcs_wait,
                            (tcs_id = claim_tcs_for_req(drv, tcs, msg))
>= 0,
                            drv->lock);

+       dev_info(drv->dev, "%s: %px GOT TCS! %d\n",
+               __func__, msg, tcs_id);
+
        tcs->req[tcs_id - tcs->offset] = msg;
        set_bit(tcs_id, drv->tcs_in_use);
        if (msg->state == RPMH_ACTIVE_ONLY_STATE && tcs->type !=
ACTIVE_TCS) {

> 
> FWIW I do not see this regression on RB5 (QRB5165/SM8250) running the
> same set of AOSP images.
> 
> Regards,
> Amit Pundir
> 
> 
> 
> 
>>
>> Fixes: 58973046c1bf ("regulator: qcom-rpmh: Use PROBE_FORCE_SYNCHRONOUS")
>> Cc: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
>> Signed-off-by: Douglas Anderson <dianders@xxxxxxxxxxxx>
>> ---
>>
>>  drivers/regulator/qcom-rpmh-regulator.c | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/regulator/qcom-rpmh-regulator.c b/drivers/regulator/qcom-rpmh-regulator.c
>> index 903032b2875f..4826d60e5d95 100644
>> --- a/drivers/regulator/qcom-rpmh-regulator.c
>> +++ b/drivers/regulator/qcom-rpmh-regulator.c
>> @@ -1462,7 +1462,7 @@ MODULE_DEVICE_TABLE(of, rpmh_regulator_match_table);
>>  static struct platform_driver rpmh_regulator_driver = {
>>         .driver = {
>>                 .name = "qcom-rpmh-regulator",
>> -               .probe_type = PROBE_FORCE_SYNCHRONOUS,
>> +               .probe_type = PROBE_PREFER_ASYNCHRONOUS,
>>                 .of_match_table = of_match_ptr(rpmh_regulator_match_table),
>>         },
>>         .probe = rpmh_regulator_probe,
>> --
>> 2.40.0.348.gf938b09366-goog
>>

-- 
Kind Regards,
Caleb (they/them)