Commit 8243e636 authored by Tejun Heo's avatar Tejun Heo Committed by Jeff Garzik

pata_ali: disable ATAPI DMA

ATAPI DMA just doesn't work reliably on pata_ali.  The IDE driver can
do it but for some mysterious reason, pata_ali can't.  This patch
disables it by default and makes the driver whine during
initialization.  "pata_ali.atapi_dma" parameter is added so that user
can bypass the workaround.
Signed-off-by: default avatarTejun Heo <htejun@gmail.com>
Signed-off-by: default avatarJeff Garzik <jeff@garzik.org>
parent e52dcc48
......@@ -36,6 +36,10 @@
#define DRV_NAME "pata_ali"
#define DRV_VERSION "0.7.5"
int ali_atapi_dma = 0;
module_param_named(atapi_dma, ali_atapi_dma, int, 0644);
MODULE_PARM_DESC(atapi_dma, "Enable ATAPI DMA (0=disable, 1=enable)");
/*
* Cable special cases
*/
......@@ -269,6 +273,27 @@ static void ali_set_dmamode(struct ata_port *ap, struct ata_device *adev)
}
}
/**
* ali_warn_atapi_dma - Warn about ATAPI DMA disablement
* @adev: Device
*
* Whine about ATAPI DMA disablement if @adev is an ATAPI device.
* Can be used as ->dev_config.
*/
static void ali_warn_atapi_dma(struct ata_device *adev)
{
struct ata_eh_context *ehc = &adev->link->eh_context;
int print_info = ehc->i.flags & ATA_EHI_PRINTINFO;
if (print_info && adev->class == ATA_DEV_ATAPI && !ali_atapi_dma) {
ata_dev_printk(adev, KERN_WARNING,
"WARNING: ATAPI DMA disabled for reliablity issues. It can be enabled\n");
ata_dev_printk(adev, KERN_WARNING,
"WARNING: via pata_ali.atapi_dma modparam or corresponding sysfs node.\n");
}
}
/**
* ali_lock_sectors - Keep older devices to 255 sector mode
* @adev: Device
......@@ -283,6 +308,7 @@ static void ali_set_dmamode(struct ata_port *ap, struct ata_device *adev)
static void ali_lock_sectors(struct ata_device *adev)
{
adev->max_sectors = 255;
ali_warn_atapi_dma(adev);
}
/**
......@@ -294,6 +320,18 @@ static void ali_lock_sectors(struct ata_device *adev)
static int ali_check_atapi_dma(struct ata_queued_cmd *qc)
{
if (!ali_atapi_dma) {
/* FIXME: pata_ali can't do ATAPI DMA reliably but the
* IDE alim15x3 driver can. I tried lots of things
* but couldn't find what the actual difference was.
* If you got an idea, please write it to
* linux-ide@vger.kernel.org and cc htejun@gmail.com.
*
* Disable ATAPI DMA for now.
*/
return -EOPNOTSUPP;
}
/* If its not a media command, its not worth it */
if (atapi_cmd_type(qc->cdb[0]) == ATAPI_MISC)
return -EOPNOTSUPP;
......@@ -359,6 +397,7 @@ static struct ata_port_operations ali_20_port_ops = {
.tf_load = ata_tf_load,
.tf_read = ata_tf_read,
.check_atapi_dma = ali_check_atapi_dma,
.check_status = ata_check_status,
.exec_command = ata_exec_command,
.dev_select = ata_std_dev_select,
......@@ -438,6 +477,7 @@ static struct ata_port_operations ali_c5_port_ops = {
.check_status = ata_check_status,
.exec_command = ata_exec_command,
.dev_select = ata_std_dev_select,
.dev_config = ali_warn_atapi_dma,
.freeze = ata_bmdma_freeze,
.thaw = ata_bmdma_thaw,
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment