From mboxrd@z Thu Jan 1 00:00:00 1970 From: majun258@huawei.com (majun (F)) Date: Mon, 1 Feb 2016 21:06:38 +0800 Subject: [RFC PATCH] irq/mbigen:Fix the problem of IO remap for duplicated physical address in mbigen driver In-Reply-To: <20160201115717.GD674@leverpostej> References: <1454327094-7848-1-git-send-email-majun258@huawei.com> <20160201115717.GD674@leverpostej> Message-ID: <56AF585E.6050005@huawei.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org ? 2016/2/1 19:57, Mark Rutland ??: > On Mon, Feb 01, 2016 at 07:44:54PM +0800, MaJun wrote: >> From: Ma Jun >> >> 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 >> --- >> 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 >> >> > > . >