Re: [PATCH 2/3] dmaengine: usb-dmac: Fix PM reference leak in usb_dmac_probe()
From: Johan Hovold <johan@kernel.org>
Date: 2021-06-07 08:06:57
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dmaengine, lkml
On Thu, Jun 03, 2021 at 04:39:08PM +0530, Vinod Koul wrote:
On 31-05-21, 11:19, Johan Hovold wrote:quoted
On Mon, May 31, 2021 at 02:27:34PM +0530, Vinod Koul wrote:quoted
On 31-05-21, 14:11, yukuai (C) wrote:quoted
On 2021/05/31 12:00, Vinod Koul wrote:quoted
On 17-05-21, 16:18, Yu Kuai wrote:quoted
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.
quoted
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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.
quoted
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
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