Hi again,
On Mon, Nov 24, 2014 at 09:36:21AM -0600, Felipe Balbi wrote:
When __of_usb_find_phy() fails, it returns -ENODEV - its error code has to be returned by devm_usb_get_phy_by_phandle(). Only when the former function succeeds and try_module_get() fails should -EPROBE_DEFER be returned.
Signed-off-by: Arjun Sreedharan arjun024@gmail.com
drivers/usb/phy/phy.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
This causes a boot regression on at least NVIDIA Dalmore (I boot over NFS using a USB network adapter).
The commit message is somewhat insufficient because while it explains what the code does and asserts that it is the right thing to do, it fails to explain why.
you also fail to explain it causes a regressions with Dalmore.
I thought my explanation below was sufficient, but maybe I should say it in other words: __of_usb_find_phy() returns -ENODEV if no PHY was found to be registered for a given phandle. That causes the driver to abort probing with a -ENODEV error and does not trigger the probe deferral that'd be necessary to get the host controller to find the PHY the next time it was triggered.
right, and before $subject dev_usb_get_phy_by_phandle() was overwriting whatever error code passed by __of_usb_find_phy() to -EPROBE_DEFER.
This is really the correct patch, we shouldn't be overwritting the error passed in by upper layers.
No, it's very obviously not the correct patch if it causes a regression.
or it exposes a bug elsewhere :-)
still, if you send your patch as a proper patch, I'll queue it as it definitely makes sense to not return -ENODEV when we have a phandle.