Hi,
On 09-12-18 16:07, Stephan Gerhold wrote:
On Sun, Dec 09, 2018 at 04:44:16PM +0200, Andy Shevchenko wrote:
On Thu, Dec 6, 2018 at 8:49 PM Stephan Gerhold <stephan@xxxxxxxxxxx> wrote:
Commit 211f658b7b40 ("usb: dwc3: pci: Use devm functions to get
the phy GPIOs") changed the code to claim the PHY GPIOs permanently
for Intel Baytrail devices.
This causes issues when the actual PHY driver attempts to claim the
same GPIO descriptors. For example, tusb1210 now fails to probe with:
tusb1210: probe of dwc3.0.auto.ulpi failed with error -16 (EBUSY)
dwc3-pci needs to turn on the PHY once before dwc3 is loaded, but
usually the PHY driver will then hold the GPIOs to turn off the
PHY when requested (e.g. during suspend).
To fix the problem, this reverts the commit to restore the old
behavior to put the GPIOs immediately after usage.
Link: https://www.spinics.net/lists/linux-usb/msg174681.html
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Stephan Gerhold <stephan@xxxxxxxxxxx>
---
drivers/usb/dwc3/dwc3-pci.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/drivers/usb/dwc3/dwc3-pci.c b/drivers/usb/dwc3/dwc3-pci.c
index 842795856bf4..fdc6e4e403e8 100644
--- a/drivers/usb/dwc3/dwc3-pci.c
+++ b/drivers/usb/dwc3/dwc3-pci.c
@@ -170,20 +170,20 @@ static int dwc3_pci_quirks(struct dwc3_pci *dwc)
* put the gpio descriptors again here because the phy driver
* might want to grab them, too.
*/
- gpio = devm_gpiod_get_optional(&pdev->dev, "cs",
- GPIOD_OUT_LOW);
+ gpio = gpiod_get_optional(&pdev->dev, "cs", GPIOD_OUT_LOW);
if (IS_ERR(gpio))
return PTR_ERR(gpio);
gpiod_set_value_cansleep(gpio, 1);
+ gpiod_put(gpio);
- gpio = devm_gpiod_get_optional(&pdev->dev, "reset",
- GPIOD_OUT_LOW);
+ gpio = gpiod_get_optional(&pdev->dev, "reset", GPIOD_OUT_LOW);
if (IS_ERR(gpio))
return PTR_ERR(gpio);
if (gpio) {
gpiod_set_value_cansleep(gpio, 1);
+ gpiod_put(gpio);
usleep_range(10000, 11000);
If something happens to GPIO line in between of these lines, the sleep
might become obsolete. Shouldn't gpiod_put() be placed after?
That's a good point, but I believe this would be more appropriately
fixed in a separate patch, since this is just an exact revert of
211f658b7b40 ("usb: dwc3: pci: Use devm functions to get the phy GPIOs")
(This is the way it was written when it was added to mainline 4 years
ago...)
I can send a separate patch for this, or would you like to?
Properly fixing this would require releasing *both* GPIOs *after* the
ULPI vendor and product IDs have been read. Which will require adding
some generic callback just for this to the generic non platform/pci
specific dwc3 code. Which IMHO is not worth the trouble since in
practice this is not really a problem.
Regards,
Hans
