From 032af1ce16d496b825adde0fa03948785ee16830 Mon Sep 17 00:00:00 2001 From: Alan Date: Thu, 1 Mar 2007 17:36:46 +0000 Subject: [PATCH] libata-core: Fix simplex handling The initial simplex handling code is fooled if you suspend and resume. This also causes problems with some single channel controllers which claim to be simplex. The fix is fairly simple, instead of keeping a flag to remember if we gave away the simplex channel we remember the actual owner. As the owner is always part of the host_set we don't even need a refcount. Knowing the owner also means we can reassign simplex DMA channels in future hotplug code etc if we need to Signed-off-by: Alan Cox (and a signed-off for the patch I sent before while I remember) Signed-off-by: Jeff Garzik --- drivers/ata/libata-core.c | 5 ++--- include/linux/libata.h | 3 +-- 2 files changed, 3 insertions(+), 5 deletions(-) diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c index ac3d1204ea3..eb59f167d66 100644 --- a/drivers/ata/libata-core.c +++ b/drivers/ata/libata-core.c @@ -2556,12 +2556,11 @@ int ata_set_mode(struct ata_port *ap, struct ata_device **r_failed_dev) * host channels are not permitted to do so. */ if (used_dma && (ap->host->flags & ATA_HOST_SIMPLEX)) - ap->host->simplex_claimed = 1; + ap->host->simplex_claimed = ap; /* step5: chip specific finalisation */ if (ap->ops->post_set_mode) ap->ops->post_set_mode(ap); - out: if (rc) *r_failed_dev = dev; @@ -3444,7 +3443,7 @@ static void ata_dev_xfermask(struct ata_device *dev) "device is on DMA blacklist, disabling DMA\n"); } - if ((host->flags & ATA_HOST_SIMPLEX) && host->simplex_claimed) { + if ((host->flags & ATA_HOST_SIMPLEX) && host->simplex_claimed != ap) { xfer_mask &= ~(ATA_MASK_MWDMA | ATA_MASK_UDMA); ata_dev_printk(dev, KERN_WARNING, "simplex DMA is claimed by " "other device, disabling DMA\n"); diff --git a/include/linux/libata.h b/include/linux/libata.h index 045fb3a72d5..3f89d13c2e9 100644 --- a/include/linux/libata.h +++ b/include/linux/libata.h @@ -403,8 +403,7 @@ struct ata_host { void *private_data; const struct ata_port_operations *ops; unsigned long flags; - int simplex_claimed; /* Keep seperate in case we - ever need to do this locked */ + struct ata_port *simplex_claimed; /* channel owning the DMA */ struct ata_port *ports[0]; }; -- 2.41.1