lkml.org 
[lkml]   [2014]   [Dec]   [4]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] usb: phy: Restore deferred probing path
Hello.

On 12/4/2014 3:06 PM, Thierry Reding wrote:

> From: Thierry Reding <treding@nvidia.com>

> Commit 1290a958d48e ("usb: phy: propagate __of_usb_find_phy()'s error on
> failure") broke platforms that rely on deferred probing to order probing
> of PHY and host controller drivers. The reason is that the commit simply
> propagates errors from __of_usb_find_phy(), which returns -ENODEV if no
> PHY has been registered yet for a given device tree node. The only case
> in which -EPROBE_DEFER would now be returned is if try_module_get() did
> fail, which does not make sense.

> The correct thing to do is to return -EPROBE_DEFER if a PHY hasn't been
> registered yet. The only condition under which it makes sense to return
> -ENODEV is if the device tree node representing the PHY has been
> disabled (via the status property) because in that case the PHY will
> never be registered.

> This patch addresses the problem by making __of_usb_find_phy() return an
> appropriate error code while keeping in line with the above-mentioned
> commit to propagate error codes rather than overwriting them. At the
> same time the check for a valid PHY is decoupled from the check for the
> try_module_get() call and a separate error code is returned if the
> latter fails.

> Signed-off-by: Thierry Reding <treding@nvidia.com>
> ---
> drivers/usb/phy/phy.c | 14 ++++++++++----
> 1 file changed, 10 insertions(+), 4 deletions(-)

> diff --git a/drivers/usb/phy/phy.c b/drivers/usb/phy/phy.c
> index b4066a001ba0..2f9735b35338 100644
> --- a/drivers/usb/phy/phy.c
> +++ b/drivers/usb/phy/phy.c
[...]
> @@ -190,10 +193,13 @@ struct usb_phy *devm_usb_get_phy_by_phandle(struct device *dev,
> spin_lock_irqsave(&phy_lock, flags);
>
> phy = __of_usb_find_phy(node);
> - if (IS_ERR(phy) || !try_module_get(phy->dev->driver->owner)) {
> - if (!IS_ERR(phy))
> - phy = ERR_PTR(-EPROBE_DEFER);
> + if (IS_ERR(phy)) {
> + devres_free(ptr);
> + goto err1;
> + }
>
> + if (!try_module_get(phy->dev->driver->owner)) {
> + phy = ERR_PTR(-ENODEV);
> devres_free(ptr);
> goto err1;
> }

I think devres_free() should now be called in one place, under the new
'err2' label.

WBR, Sergei



\
 
 \ /
  Last update: 2014-12-04 14:01    [W:0.092 / U:0.564 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site