Messages in this thread | | | From | Andy Shevchenko <> | Date | Thu, 1 Mar 2018 12:20:37 +0200 | Subject | Re: [PATCH v4 1/4] HID: add driver for Valve Steam Controller |
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On Thu, Mar 1, 2018 at 12:49 AM, Rodrigo Rivas Costa <rodrigorivascosta@gmail.com> wrote: > On Wed, Feb 28, 2018 at 09:21:15PM +0200, Andy Shevchenko wrote: >> On Wed, Feb 28, 2018 at 8:43 PM, Rodrigo Rivas Costa >> <rodrigorivascosta@gmail.com> wrote:
>> > + if (input) { >> >> if (!input) >> return; >> >> ? > That was because of symmetry, because further patches add more objects. > Then > if (input) > free(input); > if (battery) > free(battery); > /* in the future *( > if (input_gyro) > free(input_gyro); > > Sure, the last one can do an early return, but you break symmetry.
The generic APIs when designed properly are NULL aware at freeing resources.
So, it should look like
free(input); free(battery); free(input_gyro);
>> > + if (steam) { >> > + cancel_work_sync(&steam->work_connect); >> > + steam_unregister(steam); >> >> > + hid_set_drvdata(hdev, NULL); >> >> Hmm.. Doesn't HID do this? > > Do you mean the hid_set_drvdata(hdev, NULL)? I'm not sure, I didn't see > that on hid-core.c or hid-generic.c. And a call like this is done in > many modules... so I did the same, just to be sure.
What you are looking for is, AFAIU:
drivers/base/dd.c:902: dev_set_drvdata(dev, NULL);
>> >> > + } >> >> if (steam) { >> ... >> hid_hw_stop(hdev); >> ... >> } else { >> hid_hw_stop(hdev); >> } >> >> ? > > I have no real preference. Your version has two 'if', mine has two 'if'. > What about: > > static void steam_remove(struct hid_device *hdev) > { > struct steam_device *steam = hid_get_drvdata(hdev); > > if (!steam) { > hid_hw_stop(hdev); > return; > } > > if (steam->quirks & STEAM_QUIRK_WIRELESS) { > hid_info(hdev, "Steam wireless receiver disconnected"); > hid_hw_close(hdev); > } > hid_hw_stop(hdev); > cancel_work_sync(&steam->work_connect); > steam_unregister(steam);
> hid_set_drvdata(hdev, NULL);
w/o this one.
> }
For me my version looks more compact to read, but at the end it's up to you. Another option split if (steam) variant into helper, and thus
if (steam) steam_non_null_device_remove(); else hid_hw_stop();
But again, up to you (that's why question mark in the first place above).
-- With Best Regards, Andy Shevchenko
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