From: Tiezhu Yang <yangtiezhu@loongson.cn>
To: Stephen Boyd <sboyd@kernel.org>,
Michael Turquette <mturquette@baylibre.com>
Cc: linux-clk@vger.kernel.org, linux-kernel@vger.kernel.org,
Xuefeng Li <lixuefeng@loongson.cn>
Subject: Re: [PATCH v4 1/2] clk: hisilicon: Use correct return value about hisi_reset_init()
Date: Thu, 28 May 2020 10:27:42 +0800 [thread overview]
Message-ID: <51c21311-a301-1a55-3eb1-a11583e7df43@loongson.cn> (raw)
In-Reply-To: <159060638492.88029.3855641102752089121@swboyd.mtv.corp.google.com>
On 05/28/2020 03:06 AM, Stephen Boyd wrote:
> Quoting Tiezhu Yang (2020-05-27 07:39:21)
>> The return value about hisi_reset_init() is not correct, fix it.
>>
>> Fixes: e9a2310fb689 ("reset: hisilicon: fix potential NULL pointer dereference")
> hisi_reset_init() returns NULL on error in that commit. This patch
> doesn't make sense.
Hi Stephen,
The initial aim of this patch is to use correct return value about
hisi_reset_init(), maybe NULL is OK, but the return value in this
patch is more accurate.
In the current code, it always returns -ENOMEM when call function
hisi_reset_init() failed which is not proper, because in the function
hisi_reset_init(), devm_platform_ioremap_resource() may returns -EINVAL,
-EBUSY or -ENOMEM if failed.
devm_platform_ioremap_resource()
devm_ioremap_resource()
__devm_ioremap_resource()
static void __iomem *
__devm_ioremap_resource(struct device *dev, const struct resource *res,
enum devm_ioremap_type type)
{
resource_size_t size;
void __iomem *dest_ptr;
BUG_ON(!dev);
if (!res || resource_type(res) != IORESOURCE_MEM) {
dev_err(dev, "invalid resource\n");
return IOMEM_ERR_PTR(-EINVAL);
}
size = resource_size(res);
if (!devm_request_mem_region(dev, res->start, size, dev_name(dev))) {
dev_err(dev, "can't request region for resource %pR\n", res);
return IOMEM_ERR_PTR(-EBUSY);
}
dest_ptr = __devm_ioremap(dev, res->start, size, type);
if (!dest_ptr) {
dev_err(dev, "ioremap failed for resource %pR\n", res);
devm_release_mem_region(dev, res->start, size);
dest_ptr = IOMEM_ERR_PTR(-ENOMEM);
}
return dest_ptr;
}
Thanks,
Tiezhu Yang
>
>> Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
>> ---
>>
next prev parent reply other threads:[~2020-05-28 2:27 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-27 14:39 [PATCH v4 1/2] clk: hisilicon: Use correct return value about hisi_reset_init() Tiezhu Yang
2020-05-27 14:39 ` [PATCH v4 2/2] clk: Allow COMPILE_TEST for subdir hisilicon in Makefile Tiezhu Yang
2020-05-31 21:05 ` kbuild test robot
2020-06-02 1:43 ` Tiezhu Yang
2020-05-27 19:06 ` [PATCH v4 1/2] clk: hisilicon: Use correct return value about hisi_reset_init() Stephen Boyd
2020-05-28 2:27 ` Tiezhu Yang [this message]
2020-05-28 23:15 ` Stephen Boyd
2020-05-29 2:03 ` Tiezhu Yang
2020-05-29 3:58 ` Stephen Boyd
2020-05-29 4:02 ` Tiezhu Yang
2020-05-29 4:31 ` Stephen Boyd
2020-05-29 6:44 ` Tiezhu Yang
2020-05-29 9:36 ` Stephen Boyd
2020-05-29 10:20 ` Tiezhu Yang
2020-05-29 21:14 ` Stephen Boyd
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