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			39 lines
		
	
	
	
		
			1.4 KiB
		
	
	
	
		
			Diff
		
	
	
	
	
	
			
		
		
	
	
			39 lines
		
	
	
	
		
			1.4 KiB
		
	
	
	
		
			Diff
		
	
	
	
	
	
| From 8e0c576cded43030389bd2e9e9398bd17963bf96 Mon Sep 17 00:00:00 2001
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| From: Jonathan Bell <jonathan@raspberrypi.com>
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| Date: Mon, 16 May 2022 10:28:27 +0100
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| Subject: [PATCH 427/726] mmc: block: Don't do single-sector reads during
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|  recovery
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| 
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| See https://github.com/raspberrypi/linux/issues/5019
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| 
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| If an SD card has degraded performance such that IO operations time out
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| then the MMC block layer will leak SG DMA mappings in the swiotlb during
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| recovery. It retries the same SG and this causes the leak, as it is
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| mapped twice - once in sdhci_pre_req() and again during single-block
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| reads in sdhci_prepare_data().
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| 
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| Resetting the card (including power-cycling if a regulator for vmmc is
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| present) ought to be enough to recover a stuck state, so for now don't
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| try single-block reads in the recovery path.
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| 
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| Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>
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| ---
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|  drivers/mmc/core/block.c | 2 +-
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|  1 file changed, 1 insertion(+), 1 deletion(-)
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| 
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| diff --git a/drivers/mmc/core/block.c b/drivers/mmc/core/block.c
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| index f12e774df12a..3718a39c9dc5 100644
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| --- a/drivers/mmc/core/block.c
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| +++ b/drivers/mmc/core/block.c
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| @@ -1899,7 +1899,7 @@ static void mmc_blk_mq_rw_recovery(struct mmc_queue *mq, struct request *req)
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|  		return;
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|  	}
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|  
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| -	if (rq_data_dir(req) == READ && brq->data.blocks >
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| +	if (0 && rq_data_dir(req) == READ && brq->data.blocks >
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|  			queue_physical_block_size(mq->queue) >> 9) {
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|  		/* Read one (native) sector at a time */
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|  		mmc_blk_read_single(mq, req);
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| -- 
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| 2.33.1
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| 
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