lkml.org 
[lkml]   [2012]   [Sep]   [3]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH 3/3] i2c: nomadik: Add Device Tree support to the Nomadik I2C driver
    On Mon, Sep 03, 2012 at 11:44:48AM +0200, Wolfram Sang wrote:
    > On Mon, Sep 03, 2012 at 11:22:28AM +0200, Linus Walleij wrote:
    > > On Fri, Aug 31, 2012 at 2:23 PM, Lee Jones <lee.jones@linaro.org> wrote:
    > >
    > > (...)
    > > > static int nmk_i2c_probe(struct amba_device *adev, const struct amba_id *id)
    > > > {
    > > > int ret = 0;
    > > > struct nmk_i2c_controller *pdata = adev->dev.platform_data;
    > > > + struct device_node *np = adev->dev.of_node;
    > > > struct nmk_i2c_dev *dev;
    > > > struct i2c_adapter *adap;
    > > >
    > > > + if (np) {
    > > > + if (!pdata) {
    > >
    > > So, if no pdata is provided, we go on to allocate some ...
    > >
    > > > + pdata = devm_kzalloc(&adev->dev, sizeof(*pdata), GFP_KERNEL);
    > > > + if (!pdata) {
    > > > + ret = -ENOMEM;
    > > > + goto err_no_mem;
    > > > + }
    > > > + }
    > > > + /* Provide the default configuration as a base. */
    > > > + pdata = &u8500_i2c;
    > >
    > > Then you just override that pointer with a pointer to the local config.
    > >
    > > > + nmk_i2c_of_probe(np, pdata);
    > > > + }
    > > > +
    > > > if (!pdata)
    > > > /* No i2c configuration found, using the default. */
    > > > pdata = &u8500_i2c;
    > >
    > > This in it's entirety does not look sound. I *think* this is what you
    > > want to do,
    > > replace all of the above codde (including the last if (!pdata) clause) with:
    > >
    > > if (!pdata) {
    > > /* If no platform data passed in, use the default configuration as
    > > a base. */
    > > pdata = &u8500_i2c;
    > > if (np)
    > > /* Further, if we have a DT node, override the default with this */
    > > nmk_i2c_of_probe(np, pdata);
    > > }
    > >
    > > This makes any passed pdata take precedence, else default pdata
    > > complemented with DT info. Which is what we want.
    >
    > No. of_probe modifies pdata which in this case the default config which
    > might already be in use. So, you will get problems if you have two
    > instances with different configuration. So, we need to allocate memory
    > but copy the content of the default data. The patch above just copies
    > the pointer which is bogus.

    Agreed. I'll fixup.

    --
    Lee Jones
    Linaro ST-Ericsson Landing Team Lead
    Linaro.org │ Open source software for ARM SoCs
    Follow Linaro: Facebook | Twitter | Blog
    --
    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to majordomo@vger.kernel.org
    More majordomo info at http://vger.kernel.org/majordomo-info.html
    Please read the FAQ at http://www.tux.org/lkml/

    \
     
     \ /
      Last update: 2012-09-03 12:42    [W:0.029 / U:0.028 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site