From mboxrd@z Thu Jan 1 00:00:00 1970 From: Felipe Balbi Subject: Re: [RFC v2]: Issues implementing clock handling mechanism within UART driver Date: Fri, 29 Jul 2011 14:37:14 +0300 Message-ID: <20110729113713.GK31013__20979.2362562895$1312057847$gmane$org@legolas.emea.dhcp.ti.com> References: <1311845395-31917-1-git-send-email-govindraj.raja@ti.com> <20110729095512.GE31013@legolas.emea.dhcp.ti.com> Reply-To: balbi@ti.com Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============0086720396215370107==" Return-path: In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Mime-version: 1.0 Sender: linux-pm-bounces@lists.linux-foundation.org Errors-To: linux-pm-bounces@lists.linux-foundation.org To: Govindraj Cc: Partha Basak , Tero Kristo , balbi@ti.com, "Govindraj.R" , linux-serial@vger.kernel.org, linux-pm@lists.linux-foundation.org, linux-omap@vger.kernel.org List-Id: linux-pm@vger.kernel.org --===============0086720396215370107== Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="KaGhPsiNaI6/sRd6" Content-Disposition: inline --KaGhPsiNaI6/sRd6 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi, On Fri, Jul 29, 2011 at 04:54:44PM +0530, Govindraj wrote: > On Fri, Jul 29, 2011 at 3:25 PM, Felipe Balbi wrote: > > Hi, > > >=20 > Thanks for replying. >=20 > > On Thu, Jul 28, 2011 at 02:59:55PM +0530, Govindraj.R wrote: > >> Proposal: > >> -------- > >> =A0 =A0 =A0 1. For the UART, follow the current approach of locking th= e console in > >> =A0 =A0 =A0 =A0 =A0Idle/Suspend path before cutting the clock but usin= g pm_runtime_putsync. > >> =A0 =A0 =A0 =A0 =A0That is, continue using the prepare/resume Idle cal= ls in idle path. > > > > I believe you should be using ->prepare() to prevent that any other > > work on UART won't trigger a console_write() right now. Maybe only > > queueing the work for after ->complete() or, maybe, just ignoring the > > work and loosing some prints, dunno. > > >=20 > Yes true, for suspend path but for Idle path we don't have any such > mechanism. aha... good point ;-) > I have done clock gating in idle path integrating irq chaining patches. > hosted in gitorious here[1]. >=20 > Was consolidating whether this approach is OK, > or > Are there any other approaches that I should consider? why don't you also start queueing writes after the first call to runtime_suspend() and flush them after the first call runtime_resume()?? --=20 balbi --KaGhPsiNaI6/sRd6 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.11 (GNU/Linux) iQEcBAEBAgAGBQJOMptpAAoJEAv8Txj19kN1a1EIAIMHs3SqnpCS+xNzpHLMKZTI AbajLXZhYv62xoCKjOr/V1gNlsbEn1/P8cyufgOqrzy4nA1NGli1rUMqDbkfhYDy 3oRccBYLovJ3duxgqLhdKzj1FSP9cPE6mbeBlq2U7YplJKJtZRk5l3r/4LoMWwkf Bdfod4rMXsQwGKZQI1hBsCrlupnVrozi0YIL/Ntj3Mtu9DQDPB+pjMie2URURegO MK0O+JNO0Mz23NCljteBMOF4rEEAVI5ubYUzHvxm+cPYFuT9EjjtCutkoD3flJut 6HWKUVM+5I1MY3Cx47z2QNaAxESPSFZnfCQ6PD7xN3wxfdM+PCpUVWvwfG8iz9Q= =DE5E -----END PGP SIGNATURE----- --KaGhPsiNaI6/sRd6-- --===============0086720396215370107== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline --===============0086720396215370107==--