lkml.org 
[lkml]   [2014]   [Mar]   [22]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    From
    SubjectRe: [PATCH] i2c: mv64xxx: Fix compilation breakage
    Date
    On Friday 21 March 2014 20:17:39 Maxime Ripard wrote:
    > On Fri, Mar 21, 2014 at 11:49:59AM -0400, Paul Gortmaker wrote:
    > > On Mon, Mar 10, 2014 at 7:29 AM, Russell King - ARM Linux
    > > <linux@arm.linux.org.uk> wrote:
    > > > On Mon, Mar 10, 2014 at 11:58:08AM +0100, Maxime Ripard wrote:
    > > >> On Fri, Mar 07, 2014 at 04:08:36PM +0000, Russell King - ARM Linux wrote:
    > > >> > On Fri, Mar 07, 2014 at 03:59:30PM +0100, Maxime Ripard wrote:
    > > >> > > @@ -900,7 +902,8 @@ mv64xxx_i2c_probe(struct platform_device *pd)
    > > >> > > exit_free_irq:
    > > >> > > free_irq(drv_data->irq, drv_data);
    > > >> > > exit_reset:
    > > >> > > - if (pd->dev.of_node && !IS_ERR(drv_data->rstc))
    > > >> > > + if (pd->dev.of_node && IS_ENABLED(CONFIG_RESET_CONTROLLER) &&
    > > >> > > + !IS_ERR(drv_data->rstc))
    > > >> > > reset_control_assert(drv_data->rstc);
    > > >> >
    > > >> > Another question is... why do we need to check pd->dev.of_node here?
    > > >> > If CONFIG_RESET_CONTROLLER is set, we always try to get the reset
    > > >> > controller node, so drv_data->rstc is either going to be a valid
    > > >> > pointer, or it's going to be an error pointer - neither
    > > >> > reset_control_get() nor devm_reset_control_get return NULL.
    > > >>
    > > >> Following back on this as I was doing the patch, actually,
    > > >> drv_data->rstc will be NULL if we're not probed by DT, and hence never
    > > >> call reset_control_get, that would set an error pointer.
    > > >>
    > > >> But then, we can use IS_ERR_OR_NULL on drv_data->rstc.
    > > >
    > > > I think you can also move the devm_reset_control_get() into the main
    > > > probe function: you're only checking for -EPROBE_DEFER from it to fail,
    > > > allowing other errors to continue with the driver init. This means
    > > > that on non-OF, devm_reset_control_get() will fail with -ENOENT.
    > >
    > > Looping linux-next into the CC since this is the cause of the failure
    > > in orion5x_defconfig there, and no point in anyone else re-doing the
    > > same bisect.
    >
    > I sent a fix for this that hasn't been picked up yet:
    > http://lists.infradead.org/pipermail/linux-arm-kernel/2014-March/239069.html
    >
    > IIRC, Wolfram's away until Monday, so I guess it will be merged some
    > time next week.

    I think there is something wrong with an interface that makes you use
    IS_ERR_OR_NULL(). If you are calling reset_control_get_optional(), that'
    should not return an error when there is no reset controller listed
    in the device tree. We should still have a way to propagate -EPROBE_DEFER,
    or bail out if there is a reset controller but there is something wrong
    with it, but otherwise I'd suggest just leaving NULL as a valid pointer
    in drv_data->rstc and making sure that the reset controller functions
    can just deal with a NULL argument, so you never have to check it again.

    Arnd


    \
     
     \ /
      Last update: 2014-03-22 13:01    [W:2.698 / U:0.080 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site