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From: Kefeng Wang <wangkefeng.wang@huawei.com>
To: Saravana Kannan <saravanak@google.com>, Rob Herring <robh+dt@kernel.org>
Cc: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"Frank Rowand" <frowand.list@gmail.com>,
	<devicetree@vger.kernel.org>,
	Russell King <linux@armlinux.org.uk>,
	Linus Walleij <linus.walleij@linaro.org>,
	linux-arm-kernel <linux-arm-kernel@lists.infradead.org>,
	Ruizhe Lin <linruizhe@huawei.com>, <wangkefeng.wang@huawei.com>
Subject: Re: [PATCH 3/3] amba: Properly handle device probe without IRQ domain
Date: Wed, 25 Aug 2021 12:05:13 +0800	[thread overview]
Message-ID: <ee649111-dc07-d6db-8872-dcb692802236@huawei.com> (raw)
In-Reply-To: <CAGETcx8SY14rcd7g=Gdwmw7sUMb=jdEV+ffuNpg6btDoL1jmWw@mail.gmail.com>


On 2021/8/25 4:08, Saravana Kannan wrote:
> On Tue, Aug 24, 2021 at 1:05 PM Rob Herring <robh+dt@kernel.org> wrote:
>> +Saravana
>>
>> Saravana mentioned to me there may be some issues with this one...
>>
>>
>> On Mon, Aug 16, 2021 at 2:43 AM Kefeng Wang <wangkefeng.wang@huawei.com> wrote:
>>> of_amba_device_create() uses irq_of_parse_and_map() to translate
>>> a DT interrupt specification into a Linux virtual interrupt number.
>>>
>>> But it doesn't properly handle the case where the interrupt controller
>>> is not yet available, eg, when pl011 interrupt is connected to MBIGEN
>>> interrupt controller, because the mbigen initialization is too late,
>>> which will lead to no IRQ due to no IRQ domain found, log is shown below,
>>>    "irq: no irq domain found for uart0 !"
>>>
>>> use of_irq_get() to return -EPROBE_DEFER as above, and in the function
>>> amba_device_try_add()/amba_device_add(), it will properly handle in such
>>> case, also return 0 in other fail cases to be consistent as before.
>>>
>>> Cc: Russell King <linux@armlinux.org.uk>
>>> Cc: Rob Herring <robh+dt@kernel.org>
>>> Cc: Frank Rowand <frowand.list@gmail.com>
>>> Reported-by: Ruizhe Lin <linruizhe@huawei.com>
>>> Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
>>> ---
>>>   drivers/amba/bus.c    | 27 +++++++++++++++++++++++++++
>>>   drivers/of/platform.c |  6 +-----
>>>   2 files changed, 28 insertions(+), 5 deletions(-)
>>>
>>> diff --git a/drivers/amba/bus.c b/drivers/amba/bus.c
>>> index 36f2f42c8014..720aa6cdd402 100644
>>> --- a/drivers/amba/bus.c
>>> +++ b/drivers/amba/bus.c
>>> @@ -19,6 +19,7 @@
>>>   #include <linux/clk/clk-conf.h>
>>>   #include <linux/platform_device.h>
>>>   #include <linux/reset.h>
>>> +#include <linux/of_irq.h>
>>>
>>>   #include <asm/irq.h>
>>>
>>> @@ -371,12 +372,38 @@ static void amba_device_release(struct device *dev)
>>>          kfree(d);
>>>   }
>>>
>>> +static int of_amba_device_decode_irq(struct amba_device *dev)
>>> +{
>>> +       struct device_node *node = dev->dev.of_node;
>>> +       int i, irq = 0;
>>> +
>>> +       if (IS_ENABLED(CONFIG_OF_IRQ) && node) {
>>> +               /* Decode the IRQs and address ranges */
>>> +               for (i = 0; i < AMBA_NR_IRQS; i++) {
>>> +                       irq = of_irq_get(node, i);
>>> +                       if (irq < 0) {
>>> +                               if (irq == -EPROBE_DEFER)
>>> +                                       return irq;
>>> +                               irq = 0;
>>> +                       }
>>> +
>>> +                       dev->irq[i] = irq;
>>> +               }
>>> +       }
>>> +
>>> +       return 0;
>>> +}
>>> +
>>>   static int amba_device_try_add(struct amba_device *dev, struct resource *parent)
>>>   {
>>>          u32 size;
>>>          void __iomem *tmp;
>>>          int i, ret;
>>>
>>> +       ret = of_amba_device_decode_irq(dev);
>>> +       if (ret)
>>> +               goto err_out;
>>> +
> Similar to other resources the AMBA bus "gets" for the device, I think
> this should be moved into amba_probe() and not here. There's no reason
> to delay the addition of the device (and loading its module) because
> the IRQ isn't ready yet.

The following code in the amba_device_try_add() will be called, it uses irq[0]
and irq[1], so I put of_amba_device_decode_irq() into amba_device_try_add().

470         if (dev->irq[0])
471                 ret = device_create_file(&dev->dev, &dev_attr_irq0);
472         if (ret == 0 && dev->irq[1])
473                 ret = device_create_file(&dev->dev, &dev_attr_irq1);
474         if (ret == 0)
475                 return ret;

of_amba_device_decode_irq() in amba_device_try_add() won't lead to issue,
only delay the device add, right?

If make it into amba_probe(), the above code should be moved too, could we
make a new patch to move both of them, or don't move them?


  reply	other threads:[~2021-08-25  4:05 UTC|newest]

Thread overview: 27+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-08-16  7:46 [PATCH 0/3] " Kefeng Wang
2021-08-16  7:46 ` [PATCH 1/3] amba: Drop unused functions about APB/AHB devices add Kefeng Wang
2021-08-16  7:46 ` [PATCH 2/3] Revert "ARM: amba: make use of -1 IRQs warn" Kefeng Wang
2021-08-16  7:46 ` [PATCH 3/3] amba: Properly handle device probe without IRQ domain Kefeng Wang
2021-08-24 20:05   ` Rob Herring
2021-08-24 20:08     ` Saravana Kannan
2021-08-25  4:05       ` Kefeng Wang [this message]
2021-08-25  8:04         ` Saravana Kannan
2021-08-25  8:39           ` Kefeng Wang
2021-08-26  2:45           ` Kefeng Wang
2021-08-26  4:45             ` Saravana Kannan
2021-08-26  6:22               ` Kefeng Wang
2021-08-26  8:22               ` [BUG] amba: Remove deferred device addition Kefeng Wang
2021-08-27  0:04                 ` Saravana Kannan
2021-08-27 14:38                   ` Kefeng Wang
2021-08-27 19:09                     ` Saravana Kannan
2021-08-28  1:09                       ` Kefeng Wang
2021-09-09  3:30                         ` Saravana Kannan
2021-09-10  7:59                           ` Kefeng Wang
2022-07-05 19:25                             ` Saravana Kannan
2022-08-27 10:26                               ` Leizhen (ThunderTown)
2021-08-25 12:33         ` [PATCH 3/3] amba: Properly handle device probe without IRQ domain Rob Herring
2021-08-25 14:41           ` Kefeng Wang
2021-08-17 22:27 ` [PATCH 0/3] " Rob Herring
2021-08-23  2:19   ` Kefeng Wang
2021-08-23  9:05     ` Russell King (Oracle)
2021-08-23 10:57       ` Kefeng Wang

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