linux-kernel - Re: [RESEND PATCH v1 1/9] spmi: pmic-arb: add a print in cleanup

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Date:   Mon, 18 Oct 2021 08:16:52 +0800
From:   Fenglin Wu <quic_fenglinw@...cinc.com>
To:     Stephen Boyd <sboyd@...nel.org>, <linux-arm-msm@...r.kernel.org>,
        <linux-kernel@...r.kernel.org>
CC:     <collinsd@...eaurora.org>, <subbaram@...eaurora.org>,
        Abhijeet Dharmapurikar <adharmap@...eaurora.org>
Subject: Re: [RESEND PATCH v1 1/9] spmi: pmic-arb: add a print in cleanup_irq


On 10/15/2021 9:27 AM, Fenglin Wu wrote:
>
> On 10/15/2021 9:09 AM, Stephen Boyd wrote:
>> Quoting Fenglin Wu (2021-10-13 19:26:55)
>>> On 10/14/2021 3:35 AM, Stephen Boyd wrote:
>>>> Quoting Fenglin Wu (2021-10-12 21:15:42)
>>>>> On 10/13/2021 1:46 AM, Stephen Boyd wrote:
>>>>>> Quoting Fenglin Wu (2021-09-16 23:32:56)
>>>>>>> From: Abhijeet Dharmapurikar <adharmap@...eaurora.org>
>>>>>>>
>>>>>>> The cleanup_irq() was meant to clear and mask interrupts that were
>>>>>>> left enabled in the hardware but there was no interrupt handler
>>>>>>> registered for it. Add an error print when it gets invoked.
>>>>>> Why? Don't we get the genirq spurious irq message in this scenario?
>>>>> Thanks for reviewing the change.
>>>>>
>>>>> No, there is no existing message printed out in this special case 
>>>>> ( IRQ
>>>>> fired for not registered interrupt).
>>>> Ah I see so the irq doesn't have a flow handler? Shouldn't you call
>>>> handle_bad_irq() in this case so we get a irq descriptor print?
>>> In such case, the irq number is not valid and there won't be a valid
>>> irq_desc, hence it's not possible to call handle_bad_irq() here.
>> I mean handle_bad_irq() on the irqdesc for the spmi pmic arb chained
>> irq. Because things are not good with the chained irq.
> Okay, how about this, Update periph_interrupt() function with a return
> value, and return -EINVAL once an invalid IRQ is detected. In
> pmic_arb_chained_irq(), call handle_bad_irq() if periph_interrupt()
> returned -EINVAL.
Combined with your comments in "[PATCH v1 3/9] spmi: pmic-arb:check apid
againstlimits before calling irq handler",it seemslike that it can be
a independentpatch for handling spuriousinterrupt, something like this
in my mind:

diff --git a/drivers/spmi/spmi-pmic-arb.c b/drivers/spmi/spmi-pmic-arb.c
index 295e19f..bd01ad4 100644
--- a/drivers/spmi/spmi-pmic-arb.c
+++ b/drivers/spmi/spmi-pmic-arb.c
@@ -504,10 +504,10 @@ static void cleanup_irq(struct spmi_pmic_arb 
*pmic_arb, u16 apid, int id)
                                 irq_mask, ppid);
  }

-static void periph_interrupt(struct spmi_pmic_arb *pmic_arb, u16 apid)
+static int periph_interrupt(struct spmi_pmic_arb *pmic_arb, u16 apid)
  {
         unsigned int irq;
-       u32 status, id;
+       u32 status, id, handled = 0;
         u8 sid = (pmic_arb->apid_data[apid].ppid >> 8) & 0xF;
         u8 per = pmic_arb->apid_data[apid].ppid & 0xFF;

@@ -522,7 +522,10 @@ static void periph_interrupt(struct spmi_pmic_arb 
*pmic_arb, u16 apid)
                         continue;
                 }
                 generic_handle_irq(irq);
+               handled++;
         }
+
+       return (handled == 0) ? -EINVAL : 0;
  }

  static void pmic_arb_chained_irq(struct irq_desc *desc)
@@ -533,7 +536,7 @@ static void pmic_arb_chained_irq(struct irq_desc *desc)
         int first = pmic_arb->min_apid >> 5;
         int last = pmic_arb->max_apid >> 5;
         u8 ee = pmic_arb->ee;
-       u32 status, enable;
+       u32 status, enable, handled = 0;
         int i, id, apid;

         chained_irq_enter(chip, desc);
@@ -548,10 +551,14 @@ static void pmic_arb_chained_irq(struct irq_desc 
*desc)
                         enable = readl_relaxed(
ver_ops->acc_enable(pmic_arb, apid));
                         if (enable & SPMI_PIC_ACC_ENABLE_BIT)
- periph_interrupt(pmic_arb, apid);
+                               if (periph_interrupt(pmic_arb, apid) == 0)
+ handled++;
                 }
         }

+       if (handled == 0)
+               handle_bad_irq(desc);
+
         chained_irq_exit(chip, desc);
  }

Is this what you expected? The original patch is only for printing a 
debug message when any
sub-irq is detected as enabled but not registered, some other sub-IRQ 
maybe still valid and
be handled after that, which means the chained-irq may still be a good 
one.Should I keep
the original patch unchanged and submit a separate one to handle the 
spuriousinterrupt?