[34-longterm 033/260] sata_mv: fix broken DSM/TRIM support (v2)

Paul Gortmaker
2011-01-02T08:07:12Z

From: Mark Lord <kernel@teksavvy.com>

commit 44b733809a5aba7f6b15a548d31a56d25bf3851c upstream.

Fix DSM/TRIM commands in sata_mv (v2).
These need to be issued using old-school "BM DMA",
rather than via the EDMA host queue.

Since the chips don't have proper BM DMA status,
we need to be more careful with setting the ATA_DMA_INTR bit,
since DSM/TRIM often has a long delay between "DMA complete"
and "command complete".

GEN_I chips don't have BM DMA, so no TRIM for them.

Signed-off-by: Mark Lord <mlord@pobox.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
---
drivers/ata/sata_mv.c | 44 +++++++++++++++++++++++++++++++++++++-------
1 files changed, 37 insertions(+), 7 deletions(-)

diff --git a/drivers/ata/sata_mv.c b/drivers/ata/sata_mv.c
index 71cc0d4..39af57a 100644
--- a/drivers/ata/sata_mv.c
+++ b/drivers/ata/sata_mv.c
@@ -1886,19 +1886,25 @@ static void mv_bmdma_start(struct ata_queued_cmd *qc)
* LOCKING:
* Inherited from caller.
*/
-static void mv_bmdma_stop(struct ata_queued_cmd *qc)
+static void mv_bmdma_stop_ap(struct ata_port *ap)
{
- struct ata_port *ap = qc->ap;
void __iomem *port_mmio = mv_ap_base(ap);
u32 cmd;

/* clear start/stop bit */
cmd = readl(port_mmio + BMDMA_CMD);
- cmd &= ~ATA_DMA_START;
- writelfl(cmd, port_mmio + BMDMA_CMD);
+ if (cmd & ATA_DMA_START) {
+ cmd &= ~ATA_DMA_START;
+ writelfl(cmd, port_mmio + BMDMA_CMD);
+
+ /* one-PIO-cycle guaranteed wait, per spec, for HDMA1:0 transition */
+ ata_sff_dma_pause(ap);
+ }
+}

- /* one-PIO-cycle guaranteed wait, per spec, for HDMA1:0 transition */
- ata_sff_dma_pause(ap);
+static void mv_bmdma_stop(struct ata_queued_cmd *qc)
+{
+ mv_bmdma_stop_ap(qc->ap);
}

/**
@@ -1922,8 +1928,21 @@ static u8 mv_bmdma_status(struct ata_port *ap)
reg = readl(port_mmio + BMDMA_STATUS);
if (reg & ATA_DMA_ACTIVE)
status = ATA_DMA_ACTIVE;
- else
+ else if (reg & ATA_DMA_ERR)
status = (reg & ATA_DMA_ERR) | ATA_DMA_INTR;
+ else {
+ /*
+ * Just because DMA_ACTIVE is 0 (DMA completed),
+ * this does _not_ mean the device is "done".
+ * So we should not yet be signalling ATA_DMA_INTR
+ * in some cases. Eg. DSM/TRIM, and perhaps others.
+ */
+ mv_bmdma_stop_ap(ap);
+ if (ioread8(ap->ioaddr.altstatus_addr) & ATA_BUSY)
+ status = 0;
+ else
+ status = ATA_DMA_INTR;
+ }
return status;
}

@@ -1983,6 +2002,9 @@ static void mv_qc_prep(struct ata_queued_cmd *qc)

switch (tf->protocol) {
case ATA_PROT_DMA:
+ if (tf->command == ATA_CMD_DSM)
+ return;
+ /* fall-thru */
case ATA_PROT_NCQ:
break; /* continue below */
case ATA_PROT_PIO:
@@ -2082,6 +2104,8 @@ static void mv_qc_prep_iie(struct ata_queued_cmd *qc)
if ((tf->protocol != ATA_PROT_DMA) &&
(tf->protocol != ATA_PROT_NCQ))
return;
+ if (tf->command == ATA_CMD_DSM)
+ return; /* use bmdma for this */

/* Fill in Gen IIE command request block */
if (!(tf->flags & ATA_TFLAG_WRITE))
@@ -2277,6 +2301,12 @@ static unsigned int mv_qc_issue(struct ata_queued_cmd *qc)

switch (qc->tf.protocol) {
case ATA_PROT_DMA:
+ if (qc->tf.command == ATA_CMD_DSM) {
+ if (!ap->ops->bmdma_setup) /* no bmdma on GEN_I */
+ return AC_ERR_OTHER;
+ break; /* use bmdma for this */
+ }
+ /* fall thru */
case ATA_PROT_NCQ:
mv_start_edma(ap, port_mmio, pp, qc->tf.protocol);
pp->req_idx = (pp->req_idx + 1) & MV_MAX_Q_DEPTH_MASK;
--
1.7.3.3