diff options
Diffstat (limited to 'drivers/ata/sata_sil24.c')
| -rw-r--r-- | drivers/ata/sata_sil24.c | 37 |
1 files changed, 26 insertions, 11 deletions
diff --git a/drivers/ata/sata_sil24.c b/drivers/ata/sata_sil24.c index 96fd5260446..b4c674d8376 100644 --- a/drivers/ata/sata_sil24.c +++ b/drivers/ata/sata_sil24.c @@ -832,16 +832,31 @@ static int sil24_qc_defer(struct ata_queued_cmd *qc) struct ata_link *link = qc->dev->link; struct ata_port *ap = link->ap; u8 prot = qc->tf.protocol; - int is_atapi = (prot == ATA_PROT_ATAPI || - prot == ATA_PROT_ATAPI_NODATA || - prot == ATA_PROT_ATAPI_DMA); - - /* ATAPI commands completing with CHECK_SENSE cause various - * weird problems if other commands are active. PMP DMA CS - * errata doesn't cover all and HSM violation occurs even with - * only one other device active. Always run an ATAPI command - * by itself. - */ + + /* + * There is a bug in the chip: + * Port LRAM Causes the PRB/SGT Data to be Corrupted + * If the host issues a read request for LRAM and SActive registers + * while active commands are available in the port, PRB/SGT data in + * the LRAM can become corrupted. This issue applies only when + * reading from, but not writing to, the LRAM. + * + * Therefore, reading LRAM when there is no particular error [and + * other commands may be outstanding] is prohibited. + * + * To avoid this bug there are two situations where a command must run + * exclusive of any other commands on the port: + * + * - ATAPI commands which check the sense data + * - Passthrough ATA commands which always have ATA_QCFLAG_RESULT_TF + * set. + * + */ + int is_excl = (prot == ATA_PROT_ATAPI || + prot == ATA_PROT_ATAPI_NODATA || + prot == ATA_PROT_ATAPI_DMA || + (qc->flags & ATA_QCFLAG_RESULT_TF)); + if (unlikely(ap->excl_link)) { if (link == ap->excl_link) { if (ap->nr_active_links) @@ -849,7 +864,7 @@ static int sil24_qc_defer(struct ata_queued_cmd *qc) qc->flags |= ATA_QCFLAG_CLEAR_EXCL; } else return ATA_DEFER_PORT; - } else if (unlikely(is_atapi)) { + } else if (unlikely(is_excl)) { ap->excl_link = link; if (ap->nr_active_links) return ATA_DEFER_PORT; |