From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark Brown Subject: Re: [PATCH v1 3/5] spi: Added way to check for pm support for flash devices Date: Mon, 6 Feb 2017 16:46:34 +0000 Message-ID: <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> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="3gfo2cq3tygaroym" Cc: Kamal Dasu , linux-spi , Marek Vasut , MTD Maling List , Florian Fainelli , Jayachandran C , bcm-kernel-feedback-list To: Cyrille Pitchen Return-path: Content-Disposition: inline In-Reply-To: <11cfd6da-c537-eca9-5c50-7789d5b672dd-AIFe0yeh4nAAvxtiuMwx3w@public.gmane.org> Sender: linux-spi-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: --3gfo2cq3tygaroym Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, Feb 06, 2017 at 11:44:09AM +0100, Cyrille Pitchen wrote: > Le 04/02/2017 =E0 21:47, Kamal Dasu a =E9crit : > >> What is "flash pm" and how would a client use it given that no API for > >> actually managing power is being added here? Someone looking at the A= PI > >> 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 power > management, there is nothing special about SPI flashes: they are just SPI > devices like others. So why not extend the SPI framework, if needed, with > something working for all SPI devices, not just for SPI flashes. It's already possible for SPI devices to do runtime PM. --3gfo2cq3tygaroym Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAABCAAdFiEEreZoqmdXGLWf4p/qJNaLcl1Uh9AFAliYqGkACgkQJNaLcl1U h9DtBwf8COlSE1A9lZBZw+8PUhaBp2LRJn6Vl5D5qQey+MtvioKGx8P+ffYIDy1g +/rTon2HaJpKMAwmjb/5UbU1wmfCumi6XclcPIP8sfS1wJ9+AqAqvEuWBpSeHPMN GxoTir/2OG8GdIlpmHSGg3bM1tV8Y3Zs+n5VFk9TbEN2DW4gt6X+b1rIgqq7rKQO bbXpyPpu5e0TDl9a0J3HqpKydsCZayVB/vAdlft4rZs1Cs/PNNwDMdNfXkGxbvr0 aEgDMu/O4R07lIUVRXYDt/+j99v7I93PJkO9jsbI8eAE1hn0qwTOJqFQ3uhqrWSq 07xdcpBwxqdxTxvva8Pg3q6de1dogQ== =wjUW -----END PGP SIGNATURE----- --3gfo2cq3tygaroym-- -- 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 mezzanine.sirena.org.uk ([106.187.55.193]) by bombadil.infradead.org with esmtps (Exim 4.87 #1 (Red Hat Linux)) id 1camRX-0002R0-B5 for linux-mtd@lists.infradead.org; Mon, 06 Feb 2017 16:47:09 +0000 Date: Mon, 6 Feb 2017 16:46:34 +0000 From: Mark Brown To: Cyrille Pitchen Cc: Kamal Dasu , linux-spi , Marek Vasut , MTD Maling List , Florian Fainelli , Jayachandran C , bcm-kernel-feedback-list Message-ID: <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> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="3gfo2cq3tygaroym" Content-Disposition: inline In-Reply-To: <11cfd6da-c537-eca9-5c50-7789d5b672dd@atmel.com> Subject: Re: [PATCH v1 3/5] spi: Added way to check for pm support for flash devices List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , --3gfo2cq3tygaroym Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, Feb 06, 2017 at 11:44:09AM +0100, Cyrille Pitchen wrote: > Le 04/02/2017 =E0 21:47, Kamal Dasu a =E9crit : > >> What is "flash pm" and how would a client use it given that no API for > >> actually managing power is being added here? Someone looking at the A= PI > >> 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 power > management, there is nothing special about SPI flashes: they are just SPI > devices like others. So why not extend the SPI framework, if needed, with > something working for all SPI devices, not just for SPI flashes. It's already possible for SPI devices to do runtime PM. --3gfo2cq3tygaroym Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAABCAAdFiEEreZoqmdXGLWf4p/qJNaLcl1Uh9AFAliYqGkACgkQJNaLcl1U h9DtBwf8COlSE1A9lZBZw+8PUhaBp2LRJn6Vl5D5qQey+MtvioKGx8P+ffYIDy1g +/rTon2HaJpKMAwmjb/5UbU1wmfCumi6XclcPIP8sfS1wJ9+AqAqvEuWBpSeHPMN GxoTir/2OG8GdIlpmHSGg3bM1tV8Y3Zs+n5VFk9TbEN2DW4gt6X+b1rIgqq7rKQO bbXpyPpu5e0TDl9a0J3HqpKydsCZayVB/vAdlft4rZs1Cs/PNNwDMdNfXkGxbvr0 aEgDMu/O4R07lIUVRXYDt/+j99v7I93PJkO9jsbI8eAE1hn0qwTOJqFQ3uhqrWSq 07xdcpBwxqdxTxvva8Pg3q6de1dogQ== =wjUW -----END PGP SIGNATURE----- --3gfo2cq3tygaroym--