From: Johan Hovold <johan@kernel.org>
To: Vinod Koul <vkoul@kernel.org>
Cc: "yukuai (C)" <yukuai3@huawei.com>,
mcoquelin.stm32@gmail.com, alexandre.torgue@foss.st.com,
michal.simek@xilinx.com, dmaengine@vger.kernel.org,
linux-kernel@vger.kernel.org,
linux-stm32@st-md-mailman.stormreply.com,
linux-arm-kernel@lists.infradead.org, yi.zhang@huawei.com
Subject: Re: [PATCH 2/3] dmaengine: usb-dmac: Fix PM reference leak in usb_dmac_probe()
Date: Mon, 7 Jun 2021 10:06:44 +0200 [thread overview]
Message-ID: <YL3TlDqe4KSr3ICl@hovoldconsulting.com> (raw)
In-Reply-To: <YLi4VGwzrat8wJHP@vkoul-mobl>
On Thu, Jun 03, 2021 at 04:39:08PM +0530, Vinod Koul wrote:
> On 31-05-21, 11:19, Johan Hovold wrote:
> > On Mon, May 31, 2021 at 02:27:34PM +0530, Vinod Koul wrote:
> > > On 31-05-21, 14:11, yukuai (C) wrote:
> > > > On 2021/05/31 12:00, Vinod Koul wrote:
> > > > > On 17-05-21, 16:18, Yu Kuai wrote:
> > > > > > pm_runtime_get_sync will increment pm usage counter even it failed.
> > > > > > Forgetting to putting operation will result in reference leak here.
> > > > > > Fix it by replacing it with pm_runtime_resume_and_get to keep usage
> > > > > > counter balanced.
> > > Yes the rumtime_pm is disabled on failure here and the count would have
> > > no consequence...
> >
> > You should still balance the PM usage counter as it isn't reset for
> > example when reloading the driver.
>
> Should I driver trust that on load PM usage counter is balanced and not
> to be reset..?
Not sure what you're asking here. But a driver should never leave the PM
usage counter unbalanced.
> > Using pm_runtime_resume_and_get() is one way of handling this, but
> > alternatively you could also move the error_pm label above the
> > pm_runtime_put() in the error path.
>
> That would be a better way I think
Johan
next prev parent reply other threads:[~2021-06-07 8:06 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-17 8:18 [PATCH 0/3] cleanup patches for PM reference leak Yu Kuai
2021-05-17 8:18 ` [PATCH 1/3] dmaengine: stm32-mdma: fix PM reference leak in stm32_mdma_alloc_chan_resourc() Yu Kuai
2021-05-31 4:03 ` Vinod Koul
2021-05-17 8:18 ` [PATCH 2/3] dmaengine: usb-dmac: Fix PM reference leak in usb_dmac_probe() Yu Kuai
2021-05-31 4:00 ` Vinod Koul
2021-05-31 6:11 ` yukuai (C)
2021-05-31 8:57 ` Vinod Koul
2021-05-31 9:19 ` Johan Hovold
2021-06-03 11:09 ` Vinod Koul
2021-06-07 8:06 ` Johan Hovold [this message]
2021-06-07 10:19 ` Vinod Koul
2021-07-05 8:41 ` yukuai (C)
2021-07-06 10:49 ` Vinod Koul
2021-05-17 8:18 ` [PATCH 3/3] dmaengine: zynqmp_dma: Fix PM reference leak in zynqmp_dma_alloc_chan_resourc() Yu Kuai
2021-05-31 4:03 ` Vinod Koul
2021-05-29 9:13 ` [PATCH 0/3] cleanup patches for PM reference leak yukuai (C)
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=YL3TlDqe4KSr3ICl@hovoldconsulting.com \
--to=johan@kernel.org \
--cc=alexandre.torgue@foss.st.com \
--cc=dmaengine@vger.kernel.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-stm32@st-md-mailman.stormreply.com \
--cc=mcoquelin.stm32@gmail.com \
--cc=michal.simek@xilinx.com \
--cc=vkoul@kernel.org \
--cc=yi.zhang@huawei.com \
--cc=yukuai3@huawei.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
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;
as well as URLs for NNTP newsgroup(s).