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ohci1394: steps to implement suspend/resume

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I did a quick shot on what I described and the appended patch
does the first thing needed for working suspend/resume
in ohci1394 which is HW de- and re-initialisation.

It works with suspend2disk on my Ricoh R5C552 IEEE 1394 Controller
with the 2.6.17 kernel to the extent that if I call dvgrab --interactive
after suspend2disk without unloading ohci1394, it does not lock up
dvgrab with 100% CPU but properly connects to the camera, given
that I first unplug and plug the camera after coming back from
suspend.

I guess that could be fixed by forcing a bus reset in the resume
function.

I cannot test suspend to RAM here at the moment and should
follow the guidelines in Documentation/power/pci.txt also,
so this is rather a quick report than a finished patch and
there are some rough edges:

However, with this patch, I have to unload at least some in-kernel
users of ohci1394 like dv1394 or video1394 before suspending.

Not doing that caused an Oops and a bad tasklet error, probably from
not handling ISO tasklets during suspend/resume properly.

Maybe these can be temporarily cleared or unregistered and
re-registered for suspend/resume with help from the other
layers or from the highlevel 1394 core, but I do not really
know what these do.

But this patch provides a useful base to start from and is
already of much help for people which do not need dv1394
and video1394 or can unload them at least during suspend.

I cannot test function with sbp2 at the moment, but raw1394
seems to work fine.

Signed-off-by: Bernhard Kaindl <bk@fsfe.org>

Update 1: merge with previous two ohci1394 suspend/resume patches
Update 2: version for application on top of Linux 2.6.19-rc4

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
This commit is contained in:
Bernhard Kaindl 2006-09-06 14:58:30 +02:00 committed by Stefan Richter
parent f9edc4f5c1
commit f011bf085c
1 changed files with 79 additions and 15 deletions
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94
drivers/ieee1394/ohci1394.c
View file

@ -3531,6 +3531,9 @@ static void ohci1394_pci_remove(struct pci_dev *pdev)
#ifdef CONFIG_PM
static int ohci1394_pci_resume (struct pci_dev *pdev)
{
int err;
struct ti_ohci *ohci;
/* PowerMac resume code comes first */
#ifdef CONFIG_PPC_PMAC
if (machine_is(powermac)) {
@ -3545,28 +3548,89 @@ static int ohci1394_pci_resume (struct pci_dev *pdev)
pci_set_power_state(pdev, PCI_D0);
pci_restore_state(pdev);
return pci_enable_device(pdev);
err = pci_enable_device(pdev);
if (err)
return err;
ohci = pci_get_drvdata(pdev);
if (!ohci)
return -1; /* or which exit status to use? */
PRINT(KERN_DEBUG, "resume called");
/* The following lines are copied from ohci1394_pci_probe(): */
/* Start off with a soft reset, to clear everything to a sane
* state. */
ohci_soft_reset(ohci);
/* Now enable LPS, which we need in order to start accessing
* most of the registers. In fact, on some cards (ALI M5251),
* accessing registers in the SClk domain without LPS enabled
* will lock up the machine. Wait 50msec to make sure we have
* full link enabled. */
reg_write(ohci, OHCI1394_HCControlSet, OHCI1394_HCControl_LPS);
/* Disable and clear interrupts */
reg_write(ohci, OHCI1394_IntEventClear, 0xffffffff);
reg_write(ohci, OHCI1394_IntMaskClear, 0xffffffff);
mdelay(50);
ohci_initialize(ohci);
return 0;
}
static int ohci1394_pci_suspend (struct pci_dev *pdev, pm_message_t state)
{
int err;
struct ti_ohci *ohci;
printk(KERN_INFO "%s does not fully support suspend and resume yet\n",
OHCI1394_DRIVER_NAME);
ohci = pci_get_drvdata(pdev);
if (!ohci)
return -1; /* Not sure if this is the correct return code */
PRINT(KERN_DEBUG, "suspend called");
/* clear the async DMA contexts and stop using the controller: */
hpsb_bus_reset(ohci->host);
/* The following calls are from ohci1394_pci_remove(): */
/* Clear out BUS Options */
reg_write(ohci, OHCI1394_ConfigROMhdr, 0);
reg_write(ohci, OHCI1394_BusOptions,
(reg_read(ohci, OHCI1394_BusOptions) & 0x0000f007) |
0x00ff0000);
/* Clear interrupt registers */
reg_write(ohci, OHCI1394_IntMaskClear, 0xffffffff);
reg_write(ohci, OHCI1394_IntEventClear, 0xffffffff);
reg_write(ohci, OHCI1394_IsoXmitIntMaskClear, 0xffffffff);
reg_write(ohci, OHCI1394_IsoXmitIntEventClear, 0xffffffff);
reg_write(ohci, OHCI1394_IsoRecvIntMaskClear, 0xffffffff);
reg_write(ohci, OHCI1394_IsoRecvIntEventClear, 0xffffffff);
/* Disable IRM Contender */
set_phy_reg(ohci, 4, ~0xc0 & get_phy_reg(ohci, 4));
/* Clear link control register */
reg_write(ohci, OHCI1394_LinkControlClear, 0xffffffff);
/* Let all other nodes know to ignore us */
ohci_devctl(ohci->host, RESET_BUS, LONG_RESET_NO_FORCE_ROOT);
/* This stops all DMA contexts, disables interrupts,
* and clears linkEnable and LPS: */
ohci_soft_reset(ohci);
err = pci_save_state(pdev);
if (err) {
printk(KERN_ERR "%s: pci_save_state failed with %d\n",
OHCI1394_DRIVER_NAME, err);
return err;
}
err = pci_set_power_state(pdev, pci_choose_state(pdev, state));
#ifdef OHCI1394_DEBUG
if (err)
printk(KERN_DEBUG "%s: pci_set_power_state failed with %d\n",
OHCI1394_DRIVER_NAME, err);
#endif /* OHCI1394_DEBUG */
goto out;
err = pci_set_power_state(pdev, pci_choose_state(pdev, state));
if (err)
goto out;
/* PowerMac suspend code comes last */
#ifdef CONFIG_PPC_PMAC
@ -3579,8 +3643,8 @@ static int ohci1394_pci_suspend (struct pci_dev *pdev, pm_message_t state)
pmac_call_feature(PMAC_FTR_1394_ENABLE, of_node, 0, 0);
}
#endif /* CONFIG_PPC_PMAC */
return 0;
out:
return err;
}
#endif /* CONFIG_PM */