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Subject: Re: [PATCH] scsi: ufs: Fix registers dump vops caused scheduling
 while atomic
To:     Can Guo <cang@codeaurora.org>
Cc:     asutoshd@codeaurora.org, nguyenb@codeaurora.org,
        hongwus@codeaurora.org, rnayak@codeaurora.org,
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        "James E.J. Bottomley" <jejb@linux.ibm.com>,
        "Martin K. Petersen" <martin.petersen@oracle.com>,
        Stanley Chu <stanley.chu@mediatek.com>,
        Bean Huo <beanhuo@micron.com>,
        Venkat Gopalakrishnan <venkatg@codeaurora.org>,
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        "open list:ARM/QUALCOMM SUPPORT" <linux-arm-msm@vger.kernel.org>,
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From:   Bart Van Assche <bvanassche@acm.org>
Message-ID: <7931a786-8e2c-1529-8910-3d4f6c816580@acm.org>
Date:   Wed, 5 Feb 2020 14:45:22 -0800
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On 2/4/20 10:31 PM, Can Guo wrote:
> Do you mean by splitting ufshcd_print_host_regs() into two functions?
> One behaves identically same to the current function, another one called
> ufshcd_print_host_regs_nosleep(). No?

Hi Can,

Not really. I had something else in mind.

Having taken a closer look at ufs_qcom_dump_dbg_regs() I started 
wondering why there are sleep statements in that function. Is the goal 
of these sleep statements perhaps to reduce how often printk() is 
called? Has it been considered to remove all sleep calls from 
ufs_qcom_dump_dbg_regs() and instead add something like the following at 
the start of that function:

	static DEFINE_RATELIMIT_STATE(_rs,
				      DEFAULT_RATELIMIT_INTERVAL,
				      DEFAULT_RATELIMIT_BURST);
									
	if (!__ratelimit(&_rs))
		return;


Thanks,

Bart.