Return-Path: Date: Sun, 8 Oct 2017 00:53:11 +0200 From: Sebastian Reichel To: Johan Hovold Cc: =?iso-8859-1?Q?Fr=E9d=E9ric?= Danis , robh@kernel.org, marcel@holtmann.org, loic.poulain@gmail.com, lukas@wunner.de, hdegoede@redhat.com, linux-bluetooth@vger.kernel.org, linux-serial@vger.kernel.org, linux-acpi@vger.kernel.org Subject: Re: [PATCH 2/2] ACPI / scan: Fix enumeration for special UART devices Message-ID: <20171007225311.lvli7rkhv3bebq2j@earth> References: <1507107090-15992-1-git-send-email-frederic.danis.oss@gmail.com> <1507107090-15992-3-git-send-email-frederic.danis.oss@gmail.com> <20171007151934.GJ2618@localhost> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="w6zxr37su6uwuyy7" In-Reply-To: <20171007151934.GJ2618@localhost> List-ID: --w6zxr37su6uwuyy7 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi, On Sat, Oct 07, 2017 at 05:19:34PM +0200, Johan Hovold wrote: > On Wed, Oct 04, 2017 at 10:51:30AM +0200, Fr=E9d=E9ric Danis wrote: > > UART devices is expected to be enumerated by SerDev subsystem. > >=20 > > During ACPI scan, serial devices behind SPI, I2C or UART buses are not > > enumerated, allowing them to be enumerated by their respective parents. > >=20 > > Rename *spi_i2c_slave* to *serial_bus_slave* as this will be used for s= erial > > devices on serial buses (SPI, I2C or UART). > >=20 > > On Macs an empty ResourceTemplate is returned for uart slaves. > > Instead the device properties "baud", "parity", "dataBits", "stopBits" = are > > provided. Add a check for "baud" in acpi_is_serial_bus_slave(). > >=20 > > Signed-off-by: Fr=E9d=E9ric Danis >=20 > So just to reiterate what I just mentioned in a comment to one of Hans's > hci_bcm patches: >=20 > This one would silently break PM for such devices on any system which > does not have serdev enabled (as the corresponding platform devices > would no longer be registered). And with serdev enabled, hciattach > (btattach) would start failing as the tty device would no longer be > registered (but I assume everyone is aware of that, and fine with it, by > now). >=20 > Perhaps the hci_bcm driver should start depending on > SERIAL_DEV_CTRL_TTYPORT when ACPI is enabled? ACPI and DT both need SERIAL_DEV_CTRL_TTYPORT to work properly, since SERIAL_DEV_CTRL_TTYPORT is the only controller implemented for serdev. If any other controller is implemented that one could also be used. I wonder if we should just hide SERIAL_DEV_CTRL_TTYPORT and enable it together with SERDEV. I suspect that we won't see any other controller (it would be a UART device, that is not registered as tty device) in the next few years and the extra option seems to confuse people. -- Sebastian --w6zxr37su6uwuyy7 Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEE72YNB0Y/i3JqeVQT2O7X88g7+poFAlnZWtIACgkQ2O7X88g7 +ppeCQ/+NS4F2sjsj3X1tKY0nFNrdt7Z/yRgHLPw/dKygmqMEp5EfX4S2Xao5vsQ fnMgndg7wRYg4j87VfQS6EKB8rIafR3+97vb2GegWAIAVoTdnc/kIrpTAfUmKPrf 22jtA5DZbqlyHGfiDTyWHQnBXbE0grGVoHZhg+CfmkSH4uryx4pPhN7SyyHNjRsW +nDiV/RvmvIqX7qpvR4iQ0jXxCCMZAzv8OTucUVvSrSTqWgSRs0qMh+Zmgero3tI tZXAc2VP6VyVT033I7SBtj5j9V76tRjhGdiUcfC6fIuq91mJUK/ofNzlct5ej7M0 HAFTy+mvNlmEm9DIHDYYF3Enm8hI4oArvYhnXrNf47HtFfgXbxG0BuPeLfwHAjwk 6OlcJ+p96SUIvtKyMiYMYDqAbSS5M6B29glfNAtjYFP74CeDJFZB3RTteFpS3LDa cFAIQGKC3PncXdPWJpsncwWuq2zJ6VygehYXfjl0vwfFfILnmDcKuTM12JBkV/Sh P2dZqFq+kDUPN/jxLD71J80F0TKVl6IMI4CK5WbSxPxmLrIfP200KuyqmpSJ94vX nhmH45sa0F94HfwN/L5aIfr+8bhl9FPwaMmEZ/Swr9iKUpGwm1S1Z5iz4RDnIaNu agzYQ3Cow0PfvrKaDA5RAjcnkmPFHevf0yDEVU5D/ZEwd9xjBHc= =vRL5 -----END PGP SIGNATURE----- --w6zxr37su6uwuyy7--