From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mezzanine.sirena.org.uk ([106.187.55.193]:57684 "EHLO mezzanine.sirena.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755302AbbLBNaY (ORCPT ); Wed, 2 Dec 2015 08:30:24 -0500 Date: Wed, 2 Dec 2015 13:30:10 +0000 From: Mark Brown To: Charles Keepax Cc: linux-clk@vger.kernel.org, linux-i2c@vger.kernel.org, linux-spi@vger.kernel.org, linux@arm.linux.org.uk, mturquette@baylibre.com, sboyd@codeaurora.org, wsa@the-dreams.de Message-ID: <20151202133010.GJ1929@sirena.org.uk> References: <20151124173718.GK18889@ck-lbox> <20151202125855.GB6058@localhost.localdomain> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="r7YfqnGwAF7PgTLe" In-Reply-To: <20151202125855.GB6058@localhost.localdomain> Subject: Re: Handling clocks on external busses Sender: linux-clk-owner@vger.kernel.org List-ID: --r7YfqnGwAF7PgTLe Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Wed, Dec 02, 2015 at 12:58:55PM +0000, Charles Keepax wrote: > So after a bit more digging it seems this has been mitigated slightly > as a lot of SPI driver have been updated to execute transfers in > thread rather than from a worker thread and it seems the clock > framework lets you re-enter the locked sections if called from the > same thread. No, this isn't something the drivers support (it's a framework feature) and it isn't something that we're guaranteed to do, if the bus is busy we defer to the thread and it's possible the drivers might do something multi-threaded themselves. It might work a lot of the time but it's never going to be guaranteed to work. --r7YfqnGwAF7PgTLe Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQEcBAEBCAAGBQJWXvJhAAoJECTWi3JdVIfQA+AH/Rj5XoHAusUguUDYc4NViJGW evlxnShud6Y4PKjbRvsJMb2sjO9REmwxXjKMSMrR3fBaGRDlCUWybrK5bu4YXW1U RkoykLwpbwEqqQ6RSGN9bvh9xuaQoRKTNHJfyFcVw8puFFHooo9c5RHN+UnaeavR o1rSdWyah01z2SS8hnKMKvs6FclOnpku02STFVZxRaH9vtiBPkBLS1uGMX/54yE1 c3yhW3PGcllG4ieJlcfcJHH4QB0sVKvxbQ+DVxzy0/J6LxrEjhPbOpyjq4DvdrCQ hPQqCSmQS89dLW1aaqLT7TI1b2p11CxukcOy99ZFHt0lhlAi6BeM+TRyP+iYT5o= =1wIb -----END PGP SIGNATURE----- --r7YfqnGwAF7PgTLe--