[patch v2] amd74xx: fix hang on resume from ram

Jason Lunz
2006-07-26T02:45:29Z

The amd74xx driver needs to reprogram each drive's PIO timings as well
as the DMA timings on resume from s2ram. Otherwise, my
nforce3-150-based laptop hangs hard when ide_start_power_step() calls
drive->hwif->ide_dma_check(drive).

Suspend/resume from ram now works with the disk and the cdrom under
load, both with and without DMA enabled.

Signed-off-by: Jason Lunz <lunz@falooley.org>
---

I've incorporated improvements helpfully suggested by David Brownell and
Pavel Machek.

I'm hardcoding a maximum of 2 ide channels, but other aspects of this
driver (like the amd_80w global) are already doing that.

DMA is re-enabled on resume even if it wasn't on at suspend, but that
doesn't look unusual in drivers/ide/pci.

drivers/ide/pci/amd74xx.c | 58 ++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 58 insertions(+)

Index: linux-2.6.18-rc2-git1/drivers/ide/pci/amd74xx.c
===================================================================
--- linux-2.6.18-rc2-git1.orig/drivers/ide/pci/amd74xx.c
+++ linux-2.6.18-rc2-git1/drivers/ide/pci/amd74xx.c
@@ -83,6 +83,8 @@
static ide_pci_device_t *amd_chipset;
static unsigned int amd_80w;
static unsigned int amd_clock;
+#define AMD_MAX_CHANNELS (2)
+static ide_hwif_t *amd_hwifs[AMD_MAX_CHANNELS];

static char *amd_dma[] = { "MWDMA16", "UDMA33", "UDMA66", "UDMA100", "UDMA133" };
static unsigned char amd_cyc2udma[] = { 6, 6, 5, 4, 0, 1, 1, 2, 2, 3, 3, 3, 3, 3, 3, 7 };
@@ -416,6 +418,8 @@
{
int i;

+ amd_hwifs[hwif->channel] = hwif;
+
if (hwif->irq == 0) /* 0 is bogus but will do for now */
hwif->irq = pci_get_legacy_ide_irq(hwif->pci_dev, hwif->channel);

@@ -494,6 +498,58 @@
/* 19 */ DECLARE_AMD_DEV("AMD5536"),
};

+#ifdef CONFIG_PM
+
+static int amd74xx_suspend(struct pci_dev *dev, pm_message_t state)
+{
+ pci_save_state(dev);
+
+ if (state.event == PM_EVENT_SUSPEND) {
+ pci_disable_device(dev);
+ pci_set_power_state(dev, PCI_D3hot);
+ }
+ return 0;
+}
+
+static int amd74xx_resume(struct pci_dev *dev)
+{
+ int retval = 0;
+ int i;
+
+ pci_set_power_state(dev, PCI_D0);
+ retval = pci_enable_device(dev);
+ pci_restore_state(dev);
+
+ for (i = 0; i < AMD_MAX_CHANNELS; i++) {
+ int d;
+
+ if (!amd_hwifs[i])
+ continue;
+
+ for (d = 0; d < MAX_DRIVES; ++d) {
+ ide_drive_t *drive = &amd_hwifs[i]->drives[d];
+ if (drive->present && !__ide_dma_bad_drive(drive)) {
+ /* this is the primary reason this driver needs
+ * a suspend()/resume() implementation at all.
+ * Calling amd74xx_ide_dma_check() without also
+ * calling amd74xx_tune_drive() hangs my
+ * nforce3-150 system. ide-io.c will do just
+ * that later if we're resuming from s2ram.
+ */
+ amd_hwifs[i]->tuneproc(drive, 255);
+ amd_hwifs[i]->ide_dma_check(drive);
+ }
+ }
+ }
+
+ return retval;
+}
+
+#else /* !CONFIG_PM */
+#define amd74xx_suspend
+#define amd74xx_resume
+#endif /* !CONFIG_PM */
+
static int __devinit amd74xx_probe(struct pci_dev *dev, const struct pci_device_id *id)
{
amd_chipset = amd74xx_chipsets + id->driver_data;
@@ -539,6 +595,8 @@
.name = "AMD_IDE",
.id_table = amd74xx_pci_tbl,
.probe = amd74xx_probe,
+ .suspend = amd74xx_suspend,
+ .resume = amd74xx_resume,
};

static int amd74xx_ide_init(void)