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authorTejun Heo <htejun@gmail.com>2008-08-13 07:24:16 -0400
committerJeff Garzik <jgarzik@redhat.com>2008-08-22 02:07:47 -0400
commit4bdee6c5103696a2729d3db2f235d202191788e4 (patch)
treec2862fd157fd906ab7d8fbbed72acd138ce01108 /drivers/ata/sata_mv.c
parent05944bdf6fadb5394710269df6770dde447b23ca (diff)
sata_mv: don't issue two DMA commands concurrently
sata_mv allowed issuing two DMA commands concurrently which the hardware allows. Unfortunately, libata core layer isn't ready for this yet and spews ugly warning message and malfunctions on this. Don't allow concurrent DMA commands for now. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Diffstat (limited to 'drivers/ata/sata_mv.c')
-rw-r--r--drivers/ata/sata_mv.c34
1 files changed, 10 insertions, 24 deletions
diff --git a/drivers/ata/sata_mv.c b/drivers/ata/sata_mv.c
index ad169ffbc4cb..80c655f85bc8 100644
--- a/drivers/ata/sata_mv.c
+++ b/drivers/ata/sata_mv.c
@@ -1134,30 +1134,16 @@ static int mv_qc_defer(struct ata_queued_cmd *qc)
1134 if (ap->nr_active_links == 0) 1134 if (ap->nr_active_links == 0)
1135 return 0; 1135 return 0;
1136 1136
1137 if (pp->pp_flags & MV_PP_FLAG_EDMA_EN) { 1137 /*
1138 /* 1138 * The port is operating in host queuing mode (EDMA) with NCQ
1139 * The port is operating in host queuing mode (EDMA). 1139 * enabled, allow multiple NCQ commands. EDMA also allows
1140 * It can accomodate a new qc if the qc protocol 1140 * queueing multiple DMA commands but libata core currently
1141 * is compatible with the current host queue mode. 1141 * doesn't allow it.
1142 */ 1142 */
1143 if (pp->pp_flags & MV_PP_FLAG_NCQ_EN) { 1143 if ((pp->pp_flags & MV_PP_FLAG_EDMA_EN) &&
1144 /* 1144 (pp->pp_flags & MV_PP_FLAG_NCQ_EN) && ata_is_ncq(qc->tf.protocol))
1145 * The host queue (EDMA) is in NCQ mode. 1145 return 0;
1146 * If the new qc is also an NCQ command, 1146
1147 * then allow the new qc.
1148 */
1149 if (qc->tf.protocol == ATA_PROT_NCQ)
1150 return 0;
1151 } else {
1152 /*
1153 * The host queue (EDMA) is in non-NCQ, DMA mode.
1154 * If the new qc is also a non-NCQ, DMA command,
1155 * then allow the new qc.
1156 */
1157 if (qc->tf.protocol == ATA_PROT_DMA)
1158 return 0;
1159 }
1160 }
1161 return ATA_DEFER_PORT; 1147 return ATA_DEFER_PORT;
1162} 1148}
1163 1149