From mboxrd@z Thu Jan 1 00:00:00 1970 From: Felipe Balbi Subject: Re: CONFIG_DEBUG_SHIRQ and PM Date: Wed, 26 Aug 2015 14:38:20 -0500 Message-ID: <20150826193820.GT14625@saruman.tx.rr.com> References: <20150825195830.GH27534@saruman.tx.rr.com> Reply-To: Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="HjGz34yYE1BNnn/x" Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org To: Ezequiel Garcia Cc: Felipe Balbi , Ingo Molnar , Tony Lindgren , Linux OMAP Mailing List , Linux Kernel Mailing List , Linux ARM Kernel Mailing List List-Id: linux-omap@vger.kernel.org --HjGz34yYE1BNnn/x Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi, On Wed, Aug 26, 2015 at 04:29:52PM -0300, Ezequiel Garcia wrote: > Felipe, >=20 > On 25 August 2015 at 16:58, Felipe Balbi wrote: > > Hi Ingo, > > > > I'm facing an issue with CONFIG_DEBUG_SHIRQ and pm_runtime when using > > devm_request_*irq(). > > >=20 > I may be jumping on the gun here, but I believe here's your problem. > Using devm_request_irq with shared IRQs is not a good idea. >=20 > Or at least, it forces you to handle interrupts after your device > is _completely_ removed (e.g. your IRQ cookie could be bogus). >=20 > AFAICS, the CONFIG_DEBUG_SHIRQ option is just triggering a couple > spurious interrupts, that are expected to happen anyway. >=20 > Your IRQ is shared, and so you may get any IRQ at any time, > coming from another device (not yours). >=20 > So, if I'm right, my suggestion is simple: use request_irq/free_irq > and free your IRQ before you disable your clocks, remove your device, > etc. yeah, that's just a workaround though. Specially with IRQ flags coming =66rom DT, driver might have no knowledge that its IRQ is shared to start with. Besides, removing devm_* is just a workaround to the real problem. It seems, to me at least, that drivers shouldn't be calling pm_runtime_put_sync(); pm_runtime_disable() from their ->remove(), rather the bus driver should be responsible for doing so; much usb_bus_type and pci_bus_type do. Of course, this has the side effect of requiring buses to make sure that by the time ->probe() is called, that device's clocks are stable and running and the device is active. However, that's not done today for the platform_bus_type and, frankly, that would be somewhat of a complex problem to solve, considering that different SoCs integrate IPs the way they want. Personally, I think removing devm_* is but a workaround to the real thing we're dealing with. --=20 balbi --HjGz34yYE1BNnn/x Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQIcBAEBAgAGBQJV3hWsAAoJEIaOsuA1yqREYV4QAICEVNU8BDCLm9jWGp1PX+/W qA3pIZlPhWDhnVGj6ryjygXh7IKBUXwmOAdli7JQA7OernXBlzxxY8lXE2dVw3c6 DF1v8aQV217QeXN0jHobWA5WZTyX4V60qCfXB0oDTPsA1J2qcehXgksKju9EEoJO YnQfUZVijtgNIyYJmJLSVb2khOP/+s0VNgawgi2nKW7PltDREfjZx4YjL7foJnPS WUd/SOT4Ifw5FIysXAKsC6M6FMQrvVb/KmK3+NdyTPeC39Muc4MEilYA3J0dMRKA lry/PixoGbSq3VpgIq/e5yFUwiLyzwQFPIsavvqA8ClF9CWmArBSLAJZ+s2GYdoJ u7TXYuWbx30tcfcaICCpHOtqP2ox6Jpdza9RpyTlNsxeEfHfiEpdDf+8UfBq6AHF H4+pVj4vGAFpJi0MQCJCuuXnokKDoCOYlJsvKZbzr+DStWvwefs9ND3L86NfCtt2 ghczxv87YLwnULV+JfezdqZQgDBe0gVrjKd00bRLmt7YI+Bclz90Ee/Pagf75Zjd Xvzry5yzF1lappNyHxhlEgwGHP3wcFzjLv/isOFCk0now1KgvOLoWx8amlH0d//j 9Rbmy++RLqamwXJppuPCWer4O/rLF0Nyh6OAkip9i+krNEwXI/HZTn+9KR9Z4tRk GNJKkM5YLxHe9yTxk7p7 =aWj6 -----END PGP SIGNATURE----- --HjGz34yYE1BNnn/x--