From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kamal Dasu Subject: Re: [PATCH v1 3/5] spi: Added way to check for pm support for flash devices Date: Mon, 6 Feb 2017 14:32:54 -0500 Message-ID: References: <1486164676-12912-1-git-send-email-kdasu.kdev@gmail.com> <1486164676-12912-4-git-send-email-kdasu.kdev@gmail.com> <20170204112555.p77votp5m7klygbe@sirena.org.uk> <11cfd6da-c537-eca9-5c50-7789d5b672dd@atmel.com> <20170206164634.awi4oe5e4o4w2kmj@sirena.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Cc: Cyrille Pitchen , linux-spi , Marek Vasut , MTD Maling List , Florian Fainelli , Jayachandran C , bcm-kernel-feedback-list To: Mark Brown Return-path: In-Reply-To: <20170206164634.awi4oe5e4o4w2kmj-GFdadSzt00ze9xe1eoZjHA@public.gmane.org> Sender: linux-spi-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: Patches 3-5 are not needed. I will refactor patch 1-2 and send a v2 version= . Thanks Kamal On Mon, Feb 6, 2017 at 11:46 AM, Mark Brown wrote: > On Mon, Feb 06, 2017 at 11:44:09AM +0100, Cyrille Pitchen wrote: >> Le 04/02/2017 =C3=A0 21:47, Kamal Dasu a =C3=A9crit : > >> >> What is "flash pm" and how would a client use it given that no API fo= r >> >> actually managing power is being added here? Someone looking at the = API >> >> needs to be able to figure these things out and right now I can't see >> >> how they'd do that...o > >> > The flash_pm function just indicates if m25p80 resume op that does a >> > spi_nor_pm_rescan() is needed, and by default will do nothing for >> > other platforms. So the basic idea of the patches was to execute the >> > only necessary spi_nor_pm_rescan() on resume when flash parts are >> > reset on suspend. So from controller perspective there is no > > I can't tell what this means, sorry, and writing this e-mail does not > address the incomprehensibility of the API. Why would the controller > driver have anything to do with whatever this spi_nor_pm_rescan() > operation does? > >> I don't understand why we extend in the SPI framework API to add power >> management features but only for SPI flashes. I guess concerning the pow= er >> management, there is nothing special about SPI flashes: they are just SP= I >> devices like others. So why not extend the SPI framework, if needed, wit= h >> something working for all SPI devices, not just for SPI flashes. > > It's already possible for SPI devices to do runtime PM. -- To unsubscribe from this list: send the line "unsubscribe linux-spi" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-qk0-f194.google.com ([209.85.220.194]) by bombadil.infradead.org with esmtps (Exim 4.87 #1 (Red Hat Linux)) id 1cap3I-0005g8-Ls for linux-mtd@lists.infradead.org; Mon, 06 Feb 2017 19:34:22 +0000 Received: by mail-qk0-f194.google.com with SMTP id i34so10009538qkh.3 for ; Mon, 06 Feb 2017 11:33:55 -0800 (PST) MIME-Version: 1.0 In-Reply-To: <20170206164634.awi4oe5e4o4w2kmj@sirena.org.uk> References: <1486164676-12912-1-git-send-email-kdasu.kdev@gmail.com> <1486164676-12912-4-git-send-email-kdasu.kdev@gmail.com> <20170204112555.p77votp5m7klygbe@sirena.org.uk> <11cfd6da-c537-eca9-5c50-7789d5b672dd@atmel.com> <20170206164634.awi4oe5e4o4w2kmj@sirena.org.uk> From: Kamal Dasu Date: Mon, 6 Feb 2017 14:32:54 -0500 Message-ID: Subject: Re: [PATCH v1 3/5] spi: Added way to check for pm support for flash devices To: Mark Brown Cc: Cyrille Pitchen , linux-spi , Marek Vasut , MTD Maling List , Florian Fainelli , Jayachandran C , bcm-kernel-feedback-list Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Patches 3-5 are not needed. I will refactor patch 1-2 and send a v2 version= . Thanks Kamal On Mon, Feb 6, 2017 at 11:46 AM, Mark Brown wrote: > On Mon, Feb 06, 2017 at 11:44:09AM +0100, Cyrille Pitchen wrote: >> Le 04/02/2017 =C3=A0 21:47, Kamal Dasu a =C3=A9crit : > >> >> What is "flash pm" and how would a client use it given that no API fo= r >> >> actually managing power is being added here? Someone looking at the = API >> >> needs to be able to figure these things out and right now I can't see >> >> how they'd do that...o > >> > The flash_pm function just indicates if m25p80 resume op that does a >> > spi_nor_pm_rescan() is needed, and by default will do nothing for >> > other platforms. So the basic idea of the patches was to execute the >> > only necessary spi_nor_pm_rescan() on resume when flash parts are >> > reset on suspend. So from controller perspective there is no > > I can't tell what this means, sorry, and writing this e-mail does not > address the incomprehensibility of the API. Why would the controller > driver have anything to do with whatever this spi_nor_pm_rescan() > operation does? > >> I don't understand why we extend in the SPI framework API to add power >> management features but only for SPI flashes. I guess concerning the pow= er >> management, there is nothing special about SPI flashes: they are just SP= I >> devices like others. So why not extend the SPI framework, if needed, wit= h >> something working for all SPI devices, not just for SPI flashes. > > It's already possible for SPI devices to do runtime PM.