Commit ae4c3485 authored by Mans Rullgard's avatar Mans Rullgard Committed by Tejun Heo
Browse files

ata: sata_dwc_460ex: skip dma setup for non-dma commands 



Calling dmaengine_prep_slave_sg() for non-dma ATA commands is
unnecessary at best and could be harmful if the dma driver reacts
badly to this.  It also causes this driver to print a bogus error
message in these cases.

This patch changes sata_dwc_qc_issue() to only do the dma setup
for dma commands and also reports an error to libata if if fails.

Tested-by: default avatarChristian Lamparter <chunkeey@googlemail.com>
Signed-off-by: default avatarMans Rullgard <mans@mansr.com>
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
parent e1c1bee3

drivers/ata/sata_dwc_460ex.c

+9 −26
Original line number Diff line number Diff line
@@ -1023,36 +1023,12 @@ static void sata_dwc_bmdma_start(struct ata_queued_cmd *qc) 
	sata_dwc_bmdma_start_by_tag(qc, tag);

}



/*

 * Function : sata_dwc_qc_prep_by_tag

 * arguments : ata_queued_cmd *qc, u8 tag

 * Return value : None

 * qc_prep for a particular queued command based on tag

 */

static void sata_dwc_qc_prep_by_tag(struct ata_queued_cmd *qc, u8 tag)

{

	struct dma_async_tx_descriptor *desc;

	struct ata_port *ap = qc->ap;

	struct sata_dwc_device_port *hsdevp = HSDEVP_FROM_AP(ap);



	dev_dbg(ap->dev, "%s: port=%d dma dir=%s n_elem=%d\n",

		__func__, ap->port_no, get_dma_dir_descript(qc->dma_dir),

		 qc->n_elem);



	desc = dma_dwc_xfer_setup(qc);

	if (!desc) {

		dev_err(ap->dev, "%s: dma_dwc_xfer_setup returns NULL\n",

			__func__);

		return;

	}

	hsdevp->desc[tag] = desc;

}



static unsigned int sata_dwc_qc_issue(struct ata_queued_cmd *qc)

{

	u32 sactive;

	u8 tag = qc->tag;

	struct ata_port *ap = qc->ap;

	struct sata_dwc_device_port *hsdevp = HSDEVP_FROM_AP(ap);



#ifdef DEBUG_NCQ

	if (qc->tag > 0 || ap->link.sactive > 1)
@@ -1066,7 +1042,14 @@ static unsigned int sata_dwc_qc_issue(struct ata_queued_cmd *qc) 


	if (!ata_is_ncq(qc->tf.protocol))

		tag = 0;

	sata_dwc_qc_prep_by_tag(qc, tag);



	if (ata_is_dma(qc->tf.protocol)) {

		hsdevp->desc[tag] = dma_dwc_xfer_setup(qc);

		if (!hsdevp->desc[tag])

			return AC_ERR_SYSTEM;

	} else {

		hsdevp->desc[tag] = NULL;

	}



	if (ata_is_ncq(qc->tf.protocol)) {

		sactive = core_scr_read(SCR_ACTIVE);

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