From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark Brown Subject: Re: Execute spi transfers inside FIQ (NMI) or panic Date: Wed, 26 Feb 2020 11:33:33 +0000 Message-ID: <20200226113333.GC4136@sirena.org.uk> References: <20200225155354.GF4633@sirena.org.uk> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="zCKi3GIZzVBPywwA" Cc: linux-spi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: "Herbrechtsmeier Dr.-Ing. , Stefan" Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-spi-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: --zCKi3GIZzVBPywwA Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, Feb 26, 2020 at 08:36:37AM +0100, Herbrechtsmeier Dr.-Ing. , Stefan= wrote: > I see two possible solutions. > a) The complexity is handled inside the client. The client uses the > controller exclusive and isn=E2=80=99t allowed to use the new panic trans= fer during > a normal transfer. Then someone builds a system with two devices attached to a single SPI controller... besides, you've got no mechanism for controlling when a kernel might panic or power might be lost. I'm not sure a scheme that relies on being able to control when stuff happens is going to be what you need. --zCKi3GIZzVBPywwA Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAABCgAdFiEEreZoqmdXGLWf4p/qJNaLcl1Uh9AFAl5WV4wACgkQJNaLcl1U h9Cj8AgAgZNMsG788wJYCsjCMZT2ULX1+Zz3UdAYOGSMyUntdkDcIaWXOX0WfuxR +meEYXvkm7hq4Hy4jRv+Ate1vS3s9tqDcCYmRK6rxPmHvzXiI4dnuZUqrPOP2UDE lWsIw3/rx6kdD5W+MOkMSJ3myaX7MoQIOtsAuYkzgxQxJRC8nXZFF/Sbvud/SU8G baehLUhLYHck0QNzwYVOGk4t30L8+LQy/s34ESDGb+IZ+asuTwj95jyi8MWFrCjI jq1Y8fCR4sqmZMRat0CxR/RaQr/sm7wG/L2DI9DIUO5wm0dARJp9oA/nBZU8tqhj KwcLpMFfFuVjnvoGMFNcVgq3IgzTQA== =5yJk -----END PGP SIGNATURE----- --zCKi3GIZzVBPywwA--