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From: Bart Van Assche <Bart.VanAssche@wdc.com>
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Subject: Re: [PATCH v3 8/9] blk-mq: Insert blk_pm_{add,put}_request() calls
Date: Fri, 3 Aug 2018 01:03:36 +0000
Message-ID: <9223e26eee24d595cde189daa9c121d07c2260e4.camel@wdc.com>
References: <20180802182944.14442-1-bart.vanassche@wdc.com>
         <20180802182944.14442-9-bart.vanassche@wdc.com>
         <20180802235338.GB16047@ming.t460p>
         <51cfe7ab9e54013e278072e91b59b04432488dc7.camel@wdc.com>
         <20180803001142.GD16047@ming.t460p>
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On Fri, 2018-08-03 at 08:11 +-0800, Ming Lei wrote:
+AD4- On Fri, Aug 03, 2018 at 12:08:54AM +-0000, Bart Van Assche wrote:
+AD4- +AD4- On Fri, 2018-08-03 at 07:53 +-0800, Ming Lei wrote:
+AD4- +AD4- +AD4- blk+AF8-pm+AF8-add+AF8-request() calls pm+AF8-request+AF8=
-resume() for waking up device, but
+AD4- +AD4- +AD4- it is wrong because it is async request, which can't guar=
antee device
+AD4- +AD4- +AD4- will be ready before calling .queue+AF8-rq().
+AD4- +AD4-=20
+AD4- +AD4- That's a longstanding issue and not something that has been int=
roduced by this
+AD4- +AD4- patch series. Hence patch 6/9 that issues a warning if pm+AF8-r=
equest+AF8-resume() would
+AD4- +AD4- be called.
+AD4-=20
+AD4- It is introduced by your patch, please see blk+AF8-pm+AF8-allow+AF8-r=
equest().

Did you perhaps misread my patch? Please have a look at commit c8158819d506
(+ACI-block: implement runtime pm strategy+ACI-). I think that commit from =
2013
introduced the pm+AF8-request+AF8-resume() call in blk+AF8-pm+AF8-add+AF8-r=
equest().

By the way, if you would like to see that call removed, I'm fine with
removing that call.

Thanks,

Bart.