From mboxrd@z Thu Jan 1 00:00:00 1970 Content-Type: multipart/mixed; boundary="===============6926012623801022356==" MIME-Version: 1.0 From: Oliver Neukum To: linux-nfc@lists.01.org Subject: Re: [PATCH] NFC: NCI: make parent aware in PM terms Date: Mon, 23 Aug 2021 13:52:40 +0200 Message-ID: In-Reply-To: <9219eca0-d6e9-5cec-3113-995743549332@canonical.com> List-Id: --===============6926012623801022356== Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable On 23.08.21 13:29, Krzysztof Kozlowski wrote: > On 23/08/2021 12:50, Oliver Neukum wrote: >> On 19.08.21 16:45, Krzysztof Kozlowski wrote Hi, >> I personally like it a lot because I have filters organized with it. >> Nowadays no one reads LKML itself (too big volume) so it is purely for >> archiving on lore.kernel.org for searching and for people's filters. >> >> Therefore unless someone here objects, I would prefer to Cc LKML as >> well. Anyway, netdev is important as it is tracked by patchwork. very well, It shall be done. >> As far as I can tell I am doing this for the device noted in nfc_dev. >> Could you elaborate? > I meant that it looks unusual that you don't do it for your own device > (client->dev) but for device allocated in different unit. Here, you > receive client->dev and mostly you should play only with it. > > While I am looking at this more, there is another issue actually - you > touch runtime PM of NFC/NCI core device but it's the NFC/NCI core who > should handle it's own runtime PM. Well, I looked into that and that was very difficult. The NFC core has no idea what hardware it is running on. On my test hardware as far as I can tell, the power supply of my NFC hardware is just tied to the power supply of the i2c host controller, which is a PCI device. It goes into D3cold when the i2c bus is not transferring anything. That makes it impossible to actually communicate over NFC. However, at least on USB sending a device into USB suspend with remote wakeup should work. So I do not see how to put this into NFC core. =C2=A0=C2=A0=C2=A0 Regards =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 Oliver --===============6926012623801022356==--