sata_via: Apply WD workaround only when needed on VT6421

Currently, workaround for broken WD drives is applied always, slowing
down all drives. And it has a bug - it's not applied after resume.

Apply the workaround only if the error really appears
(SErr == 0x1000500). This allows unaffected drives to run at full speed
(provided that no affected drive is connected to the controller).
Also make sure the workaround is re-applied on resume.

Tested on VT6421.
As SCR registers access is known to cause problems on VT6420 (and I
don't have it to test), keep the workaround applied always on VT6420.

Unaffected drive (Hitachi HDS721680PLA380):
Before:
$ hdparm -t --direct /dev/sdb
/dev/sdb:
 Timing O_DIRECT disk reads: 160 MB in  3.01 seconds =  53.16 MB/sec

After:
$ hdparm -t --direct /dev/sdb
/dev/sdb:
 Timing O_DIRECT disk reads: 200 MB in  3.01 seconds =  66.47 MB/sec

Affected drive (WDC WD5003ABYX-18WERA0):
Before:
$ hdparm -t --direct /dev/sda

/dev/sda:
 Timing O_DIRECT disk reads: 180 MB in  3.02 seconds =  59.51 MB/sec

After:
$ hdparm -t --direct /dev/sdb
/dev/sdb:
 Timing O_DIRECT disk reads: 156 MB in  3.03 seconds =  51.48 MB/sec
$ hdparm -t --direct /dev/sdb
/dev/sdb:
 Timing O_DIRECT disk reads: 180 MB in  3.02 seconds =  59.64 MB/sec

The first hdparm is slower because of the error:
[   50.408042] ata5: Incompatible drive: enabling workaround. This slows down transfer rate to ~60 MB/s
[   50.728052] ata5: SATA link up 1.5 Gbps (SStatus 113 SControl 310)
[   50.744834] ata5.00: configured for UDMA/133

Signed-off-by: Ondrej Zary <linux@rainbow-software.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
This commit is contained in:
Ondrej Zary 2016-02-20 12:01:53 +01:00 committed by Tejun Heo
parent 02e53293ea
commit 44a9b494f2
1 changed files with 74 additions and 7 deletions

View File

@ -73,7 +73,14 @@ enum {
SATA_EXT_PHY = (1 << 6), /* 0==use PATA, 1==ext phy */
};
struct svia_priv {
bool wd_workaround;
};
static int svia_init_one(struct pci_dev *pdev, const struct pci_device_id *ent);
#ifdef CONFIG_PM_SLEEP
static int svia_pci_device_resume(struct pci_dev *pdev);
#endif
static int svia_scr_read(struct ata_link *link, unsigned int sc_reg, u32 *val);
static int svia_scr_write(struct ata_link *link, unsigned int sc_reg, u32 val);
static int vt8251_scr_read(struct ata_link *link, unsigned int scr, u32 *val);
@ -85,6 +92,7 @@ static void vt6420_bmdma_start(struct ata_queued_cmd *qc);
static int vt6421_pata_cable_detect(struct ata_port *ap);
static void vt6421_set_pio_mode(struct ata_port *ap, struct ata_device *adev);
static void vt6421_set_dma_mode(struct ata_port *ap, struct ata_device *adev);
static void vt6421_error_handler(struct ata_port *ap);
static const struct pci_device_id svia_pci_tbl[] = {
{ PCI_VDEVICE(VIA, 0x5337), vt6420 },
@ -105,7 +113,7 @@ static struct pci_driver svia_pci_driver = {
.probe = svia_init_one,
#ifdef CONFIG_PM_SLEEP
.suspend = ata_pci_device_suspend,
.resume = ata_pci_device_resume,
.resume = svia_pci_device_resume,
#endif
.remove = ata_pci_remove_one,
};
@ -137,6 +145,7 @@ static struct ata_port_operations vt6421_sata_ops = {
.inherits = &svia_base_ops,
.scr_read = svia_scr_read,
.scr_write = svia_scr_write,
.error_handler = vt6421_error_handler,
};
static struct ata_port_operations vt8251_ops = {
@ -536,7 +545,36 @@ static int vt8251_prepare_host(struct pci_dev *pdev, struct ata_host **r_host)
return 0;
}
static void svia_configure(struct pci_dev *pdev, int board_id)
static void svia_wd_fix(struct pci_dev *pdev)
{
u8 tmp8;
pci_read_config_byte(pdev, 0x52, &tmp8);
pci_write_config_byte(pdev, 0x52, tmp8 | BIT(2));
}
static void vt6421_error_handler(struct ata_port *ap)
{
struct svia_priv *hpriv = ap->host->private_data;
struct pci_dev *pdev = to_pci_dev(ap->host->dev);
u32 serror;
/* see svia_configure() for description */
if (!hpriv->wd_workaround) {
svia_scr_read(&ap->link, SCR_ERROR, &serror);
if (serror == 0x1000500) {
ata_port_warn(ap, "Incompatible drive: enabling workaround. This slows down transfer rate to ~60 MB/s");
svia_wd_fix(pdev);
hpriv->wd_workaround = true;
ap->link.eh_context.i.flags |= ATA_EHI_QUIET;
}
}
ata_sff_error_handler(ap);
}
static void svia_configure(struct pci_dev *pdev, int board_id,
struct svia_priv *hpriv)
{
u8 tmp8;
@ -593,11 +631,15 @@ static void svia_configure(struct pci_dev *pdev, int board_id)
* https://bugzilla.kernel.org/show_bug.cgi?id=15173
* http://article.gmane.org/gmane.linux.ide/46352
* http://thread.gmane.org/gmane.linux.kernel/1062139
*
* As the fix slows down data transfer, apply it only if the error
* actually appears - see vt6421_error_handler()
* Apply the fix always on vt6420 as we don't know if SCR_ERROR can be
* read safely.
*/
if (board_id == vt6420 || board_id == vt6421) {
pci_read_config_byte(pdev, 0x52, &tmp8);
tmp8 |= 1 << 2;
pci_write_config_byte(pdev, 0x52, tmp8);
if (board_id == vt6420) {
svia_wd_fix(pdev);
hpriv->wd_workaround = true;
}
}
@ -608,6 +650,7 @@ static int svia_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
struct ata_host *host = NULL;
int board_id = (int) ent->driver_data;
const unsigned *bar_sizes;
struct svia_priv *hpriv;
ata_print_version_once(&pdev->dev, DRV_VERSION);
@ -647,11 +690,35 @@ static int svia_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
if (rc)
return rc;
svia_configure(pdev, board_id);
hpriv = devm_kzalloc(&pdev->dev, sizeof(*hpriv), GFP_KERNEL);
if (!hpriv)
return -ENOMEM;
host->private_data = hpriv;
svia_configure(pdev, board_id, hpriv);
pci_set_master(pdev);
return ata_host_activate(host, pdev->irq, ata_bmdma_interrupt,
IRQF_SHARED, &svia_sht);
}
#ifdef CONFIG_PM_SLEEP
static int svia_pci_device_resume(struct pci_dev *pdev)
{
struct ata_host *host = pci_get_drvdata(pdev);
struct svia_priv *hpriv = host->private_data;
int rc;
rc = ata_pci_device_do_resume(pdev);
if (rc)
return rc;
if (hpriv->wd_workaround)
svia_wd_fix(pdev);
ata_host_resume(host);
return 0;
}
#endif
module_pci_driver(svia_pci_driver);