On 10/30/2015 06:22 PM, Andrzej Hajda wrote:
> On 10/06/2015 11:24 AM, Archit Taneja wrote:
>> We don't check whether a previously registered mipi_dsi_device under the
>> same host shares the same virtual channel.
>>
>> Before registering, check if any of the registered devices doesn't
>> already have the same virtual channel.
>>
>> This wasn't crucial when all the devices under a host were populated via
>> DT. Now that we also support creating devices manually, we could end up
>> in a situation where a driver tries to create a device with a virtual
>> channel already taken by a device populated in DT.
>>
>> Signed-off-by: Archit Taneja <[email protected]>
> Beside few non-blcking nitpicks.
>
> Reviewed-by: Andrzej Hajda <[email protected]>
>
>> ---
>> drivers/gpu/drm/drm_mipi_dsi.c | 26 ++++++++++++++++++++++++--
>> 1 file changed, 24 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/drm_mipi_dsi.c b/drivers/gpu/drm/drm_mipi_dsi.c
>> index 46ee515..db6130a 100644
>> --- a/drivers/gpu/drm/drm_mipi_dsi.c
>> +++ b/drivers/gpu/drm/drm_mipi_dsi.c
>> @@ -123,6 +123,22 @@ static const struct device_type mipi_dsi_device_type = {
>> .release = mipi_dsi_dev_release,
>> };
>>
>> +static int __dsi_check_chan_busy(struct device *dev, void *data)
>> +{
>> + struct mipi_dsi_device *dsi = to_mipi_dsi_device(dev);
>> + u32 reg = *(u32 *) data;
>> +
>> + if (dsi && dsi->channel == reg)
> Maybe simpler would be:
>
> u32 *reg = data;
>
> if (dsi && dsi->channel == *reg)
>
This is better. I'll change it to this.
>
>
>> + return -EBUSY;
>> +
>> + return 0;
>> +}
>> +
>> +static int mipi_dsi_check_chan_busy(struct mipi_dsi_host *host, u32 reg)
>> +{
>> + return device_for_each_child(host->dev, ®, __dsi_check_chan_busy);
>> +}
>> +
>> struct mipi_dsi_device *mipi_dsi_device_new(struct mipi_dsi_host *host,
>> struct mipi_dsi_device_info *info)
>> {
>> @@ -150,14 +166,20 @@ struct mipi_dsi_device *mipi_dsi_device_new(struct mipi_dsi_host *host,
>>
>> dev_set_name(&dsi->dev, "%s.%d", dev_name(host->dev), info->reg);
>>
>> + r = mipi_dsi_check_chan_busy(host, info->reg);
>
> I know this r variable was introduced in the 1st patch, but if you will send
> next iteration
> consider replacing it with ret, looks more readable and follows file convention :)
I'll probably end up sending another iteration (or more). I'll change
the name.
Thanks,
Archit
>
> Regards
> Andrzej
>
>> + if (r)
>> + goto err;
>> +
>> r = device_register(&dsi->dev);
>> if (r) {
>> dev_err(dev, "failed to register device: %d\n", r);
>> - kfree(dsi);
>> - return ERR_PTR(r);
>> + goto err;
>> }
>>
>> return dsi;
>> +err:
>> + kfree(dsi);
>> + return ERR_PTR(r);
>> }
>> EXPORT_SYMBOL(mipi_dsi_device_new);
>>
>
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