Commit da3fecb0 authored Nov 02, 2020 by Can Guo Committed by Martin K. Petersen Nov 04, 2020

scsi: ufs: Fix unbalanced scsi_block_reqs_cnt caused by ufshcd_hold()

The scsi_block_reqs_cnt increased in ufshcd_hold() is supposed to be
decreased back in ufshcd_ungate_work() in a paired way. However, if
specific ufshcd_hold/release sequences are met, it is possible that
scsi_block_reqs_cnt is increased twice but only one ungate work is
queued. To make sure scsi_block_reqs_cnt is handled by ufshcd_hold() and
ufshcd_ungate_work() in a paired way, increase it only if queue_work()
returns true.

Link: https://lore.kernel.org/r/1604384682-15837-2-git-send-email-cang@codeaurora.org


Reviewed-by: Hongwu Su <hongwus@codeaurora.org>
Reviewed-by: Stanley Chu <stanley.chu@mediatek.com>
Reviewed-by: Bean Huo <beanhuo@micron.com>
Signed-off-by: Can Guo <cang@codeaurora.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

parent 5feed64f

drivers/scsi/ufs/ufshcd.c

+3 −3

Original line number	Diff line number	Diff line
		@@ -1627,12 +1627,12 @@ start:
		*/
		fallthrough;
		case CLKS_OFF:
		ufshcd_scsi_block_requests(hba);
		hba->clk_gating.state = REQ_CLKS_ON;
		trace_ufshcd_clk_gating(dev_name(hba->dev),
		hba->clk_gating.state);
		queue_work(hba->clk_gating.clk_gating_workq,
		&hba->clk_gating.ungate_work);
		if (queue_work(hba->clk_gating.clk_gating_workq,
		&hba->clk_gating.ungate_work))
		ufshcd_scsi_block_requests(hba);
		/*
		* fall through to check if we should wait for this
		* work to be done or not.

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