From: majun258@huawei•com (majun (F))
To: linux-arm-kernel@lists•infradead.org
Subject: [RFC PATCH] irq/mbigen:Fix the problem of IO remap for duplicated physical address in mbigen driver
Date: Mon, 1 Feb 2016 21:06:38 +0800 [thread overview]
Message-ID: <56AF585E.6050005@huawei.com> (raw)
In-Reply-To: <20160201115717.GD674@leverpostej>
? 2016/2/1 19:57, Mark Rutland ??:
> On Mon, Feb 01, 2016 at 07:44:54PM +0800, MaJun wrote:
>> From: Ma Jun <majun258@huawei•com>
>>
>> For mbigen module, there is a special case that more than one mbigen
>> device nodes use the same reg definition in DTS when these devices
>> exist in the same mbigen hardware module.
>>
>> mbigen_dev1:intc_dev1 {
>> ...
>> reg = <0x0 0xc0080000 0x0 0x10000>;
>> ...
>> };
>>
>> mbigen_dev2:intc_dev2 {
>> ...
>> reg = <0x0 0xc0080000 0x0 0x10000>;
>> ...
>> };
>
> This doesn't sound right. If they exist in the same place, and have the
> same reg, they _are_ the same device.
>
> You'll need to explain this better.
>
For a mbigen hardware module which connecte with several devices,
because these devices has different device ID,
I need to define a device node for each device in DTS file.
mbigen
|
------------------
| | |
dev1 dev2 dev3
Because of register layout,the registers related with these devices
are put together, I can't split them clearly.
So, I only make these devices which connect with
same mbigen hardware module usethe same address.
>> On this case, devm_ioremap_resource() returns fail with info
>> "can't request region for resource" because of memory region check.
>>
>> Because we only need to program 1 into corresponding bit into status
>> register of mbigen to clear the interrupt status during runtime,
>> I think we can replace devm_ioremap_resource() by devm_ioremap().
>>
>> Signed-off-by: Ma Jun <majun258@huawei•com>
>> ---
>> drivers/irqchip/irq-mbigen.c | 2 +-
>> 1 files changed, 1 insertions(+), 1 deletions(-)
>>
>> diff --git a/drivers/irqchip/irq-mbigen.c b/drivers/irqchip/irq-mbigen.c
>> index 4dd3eb8..b19e528 100644
>> --- a/drivers/irqchip/irq-mbigen.c
>> +++ b/drivers/irqchip/irq-mbigen.c
>> @@ -250,7 +250,7 @@ static int mbigen_device_probe(struct platform_device *pdev)
>> mgn_chip->pdev = pdev;
>>
>> res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>> - mgn_chip->base = devm_ioremap_resource(&pdev->dev, res);
>> + mgn_chip->base = devm_ioremap(&pdev->dev, res->start, resource_size(res));
>
> These two behaving differently doesn't seem correct either...
The problem is caused by memory region check fail because of duplicated address in devm_ioremap_resource().
For mbigen special case, there is no necessary to do this check.
Thanks
Ma Jun
>
> Mark.
>
>> if (IS_ERR(mgn_chip->base))
>> return PTR_ERR(mgn_chip->base);
>>
>> --
>> 1.7.1
>>
>>
>
> .
>
next prev parent reply other threads:[~2016-02-01 13:06 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-02-01 11:44 [RFC PATCH] irq/mbigen:Fix the problem of IO remap for duplicated physical address in mbigen driver MaJun
2016-02-01 11:57 ` Mark Rutland
2016-02-01 13:06 ` majun (F) [this message]
2016-02-01 13:25 ` Mark Rutland
2016-02-02 10:25 ` majun (F)
2016-02-02 11:43 ` Mark Rutland
2016-02-03 2:31 ` majun (F)
2016-02-03 11:16 ` Mark Rutland
2016-02-16 7:54 ` majun (F)
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=56AF585E.6050005@huawei.com \
--to=majun258@huawei$(echo .)com \
--cc=linux-arm-kernel@lists$(echo .)infradead.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox