Hi,
On 16-11-15 17:04, Chen-Yu Tsai wrote:
On Mon, Nov 16, 2015 at 11:42 PM, Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> wrote:
On Sun, 15 Nov 2015, Hans de Goede wrote:
From: Reinder de Haan <patchesrdh@xxxxxxxxx>
At least the EHCI found on the Allwinnner H3 SoC needs multiple reset
lines, the controller will not initialize while the reset for its
companion OHCI is still asserted, which means we need to de-assert
2 reset-controllers for this EHCI controller to work.
I assume that reset_control_deassert() is smart enough to maintain a
count of de-assertions, and it doesn't actually turn on the reset line
until the count drops to 0. Right?
No it doesn't. That might be a problem when 2 devices (such as EHCI / OHCI
pairs) share a reset line, one probes successfully while the other doesn't.
Hans?
Ugh, good catch Alan, so I think the best way to solve this is to
actually make reset_control do a deassert / (re)assert count like
is done already for clocks, there is bound to be more hardware out there
which shares a reset line between 2 related blocks.
I'll whip up a patch for this, submit it and then we'll see.
Regards,
Hans
Signed-off-by: Reinder de Haan <patchesrdh@xxxxxxxxx>
Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
...
@@ -229,18 +230,24 @@ static int ehci_platform_probe(struct platform_device *dev)
break;
}
}
- }
- priv->rst = devm_reset_control_get_optional(&dev->dev, NULL);
- if (IS_ERR(priv->rst)) {
- err = PTR_ERR(priv->rst);
- if (err == -EPROBE_DEFER)
- goto err_put_clks;
- priv->rst = NULL;
- } else {
- err = reset_control_deassert(priv->rst);
- if (err)
- goto err_put_clks;
+ for (rst = 0; rst < EHCI_MAX_RESETS; rst++) {
What happens on platforms that don't use OF? Or if pdata is not equal
to &ehci_platform_defaults? Can you guarantee that those platforms
will never need to turn off a reset line?
The reset control framework is OF / DT only at the moment.
Regards
ChenYu
+ priv->resets[rst] =
+ of_reset_control_get_by_index(dev->dev.of_node,
+ rst);
The style used in this file is to indent continuation lines to 2 two
stops, not to line things up with an open paren on the previous line.
The rest of the patch looks okay.
Alan Stern
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