Re: Early-boot kernel panics from udev-165/extras/ata_id/ata_id.c

[John Stanley <jpsinthemix@verizon.net>]

Fantastic... looks promising, test-identify-packet is running w/o issue, 
and boots, so far, as well. I will further test with a number of warm 
and cold boots over the next several days to see if anything crops up. 
I'm very grateful for your time and efforts with this, thanks again,
John

On 01/18/2011 10:09 AM, Tejun Heo wrote:
> Hello,
>
> Can you please test whether the following patch fixes the problem?
>
> Thanks.
>
> diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
> index 5defc74..9d46731 100644
> --- a/drivers/ata/libata-scsi.c
> +++ b/drivers/ata/libata-scsi.c
> @@ -1099,9 +1099,9 @@ static int ata_scsi_dev_config(struct scsi_device *sdev,
>   		struct request_queue *q = sdev->request_queue;
>   		void *buf;
>
> -		/* set the min alignment and padding */
> -		blk_queue_update_dma_alignment(sdev->request_queue,
> -					       ATA_DMA_PAD_SZ - 1);
> +		sdev->sector_size = ATA_SECT_SIZE;
> +
> +		/* set DMA padding */
>   		blk_queue_update_dma_pad(sdev->request_queue,
>   					 ATA_DMA_PAD_SZ - 1);
>
> @@ -1115,13 +1115,18 @@ static int ata_scsi_dev_config(struct scsi_device *sdev,
>
>   		blk_queue_dma_drain(q, atapi_drain_needed, buf, ATAPI_MAX_DRAIN);
>   	} else {
> -		/* ATA devices must be sector aligned */
>   		sdev->sector_size = ata_id_logical_sector_size(dev->id);
> -		blk_queue_update_dma_alignment(sdev->request_queue,
> -					       sdev->sector_size - 1);
>   		sdev->manage_start_stop = 1;
>   	}
>
> +	/*
> +	 * ata_pio_sectors() expect sector alignment on buffers.  ATAPI
> +	 * devices also need the alignment as IDENTIFY_PACKET is executed
> +	 * as ATA_PROT_PIO.
> +	 */
> +	blk_queue_update_dma_alignment(sdev->request_queue,
> +				       sdev->sector_size - 1);
> +
>   	if (dev->flags&  ATA_DFLAG_AN)
>   		set_bit(SDEV_EVT_MEDIA_CHANGE, sdev->supported_events);
>
>