Hi Sergei
Thank you for your reply
inserted the patch below,
I noticed libata doesn't support to use PIO mode when DMA mode is
available, is there any specific reasons?
>From d92586d8a707f06dc0b8189fd22483a9d8a753d4 Mon Sep 17 00:00:00 2001
From: Jiada Wang <jiada_wang@xxxxxxxxxx>
Date: Wed, 26 Dec 2012 17:00:39 +0900
Subject: [PATCH] libata: handle HDIO_SET_DMA & HDIO_GET_DMA ioctl
currently HDIO_SET_DMA & HDIO_GET_DMA are not handled in libata,
this patch add support to handle HDIO_SET_DMA & HDIO_GET_DMA ioctl,
which enables user to set ata device work in PIO or DMA mode.
Signed-off-by: Jiada Wang <jiada_wang@xxxxxxxxxx>
---
drivers/ata/libata-core.c | 2 +-
drivers/ata/libata-scsi.c | 36 ++++++++++++++++++++++++++++++++++++
include/linux/libata.h | 1 +
3 files changed, 38 insertions(+), 1 deletion(-)
diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 71e8385..6b16952 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -3136,7 +3136,7 @@ int ata_down_xfermask_limit(struct ata_device
*dev, unsigned int sel)
return 0;
}
-static int ata_dev_set_mode(struct ata_device *dev)
+int ata_dev_set_mode(struct ata_device *dev)
{
struct ata_port *ap = dev->link->ap;
struct ata_eh_context *ehc = &dev->link->eh_context;
diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index 2222635..beac285 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -660,6 +660,8 @@ int ata_sas_scsi_ioctl(struct ata_port *ap, struct
scsi_device *scsidev,
{
int val = -EINVAL, rc = -EINVAL;
unsigned long flags;
+ struct ata_device *dev = __ata_scsi_find_dev(ap, scsidev);
+ int dma;
switch (cmd) {
case ATA_IOC_GET_IO32:
@@ -699,6 +701,40 @@ int ata_sas_scsi_ioctl(struct ata_port *ap,
struct scsi_device *scsidev,
return -EACCES;
return ata_task_ioctl(scsidev, arg);
+ case HDIO_GET_DMA:
+ return put_user(dev->xfer_mode == dev->dma_mode,
+ (long __user *) arg);
+ case HDIO_SET_DMA:
+ if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
+ return -EACCES;
+
+ if (copy_from_user(&dma, arg, sizeof(dma)))
+ return -EFAULT;
+
+ if (dma) {
+ if (!ata_dma_enabled(dev))
+ return -EINVAL;
+
+ dev->xfer_mode = dev->dma_mode;
+ dev->xfer_shift = ata_xfer_mode2shift(dev->dma_mode);
+ if (ap->ops->set_dmamode)
+ ap->ops->set_dmamode(ap, dev);
+ } else {
+ if (dev->pio_mode == 0xff)
+ return -EINVAL;
+
+ dev->xfer_mode = dev->pio_mode;
+ dev->xfer_shift = ATA_SHIFT_PIO;
+ if (ap->ops->set_piomode)
+ ap->ops->set_piomode(ap, dev);
+ }
+
+ ata_eh_acquire(ap);
+ rc = ata_dev_set_mode(dev);
+ ata_eh_release(ap);
+
+ return rc;
+
default:
rc = -ENOTTY;
break;
diff --git a/include/linux/libata.h b/include/linux/libata.h
index 6e887c7..88664b67 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -1067,6 +1067,7 @@ extern int ata_cable_80wire(struct ata_port *ap);
extern int ata_cable_sata(struct ata_port *ap);
extern int ata_cable_ignore(struct ata_port *ap);
extern int ata_cable_unknown(struct ata_port *ap);
+extern int ata_dev_set_mode(struct ata_device *dev);
/* Timing helpers */
extern unsigned int ata_pio_need_iordy(const struct ata_device *);
--
1.7.12.3
2013/1/18 Sergei Shtylyov <sshtylyov@xxxxxxxxxx>:
> Hello.
>
>
> On 18-01-2013 11:55, Jiada Wang wrote:
>
>> The purpose of this patch is to switch SATA device in PIO mode and DMA
>> mode,
>> And get current transfer mode,
>
>
>> Please kindly give me your comments
>
>
> You posted the patch in the form on which it's hard to give comments.
> Never attach the patches (especially with non-text/plain MIME type), instert
> them inline instead.
>
>> Thanks,
>
>
>> Jiada
>
>
> MBR, Sergei
>
--
BRs
Stephen
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