From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758886AbaDJRga (ORCPT ); Thu, 10 Apr 2014 13:36:30 -0400 Received: from mezzanine.sirena.org.uk ([106.187.55.193]:47934 "EHLO mezzanine.sirena.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753221AbaDJRg1 (ORCPT ); Thu, 10 Apr 2014 13:36:27 -0400 Date: Thu, 10 Apr 2014 18:36:16 +0100 From: Mark Brown To: Harini Katakam Cc: linux-spi@vger.kernel.org, linux-kernel@vger.kernel.org, michals@xilinx.com Message-ID: <20140410173616.GC6518@sirena.org.uk> References: <1397134229-2380-1-git-send-email-harinik@xilinx.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="DaTEgnRu5pEC8TLg" Content-Disposition: inline In-Reply-To: <1397134229-2380-1-git-send-email-harinik@xilinx.com> X-Cookie: This report is filled with omissions. User-Agent: Mutt/1.5.23 (2014-03-12) X-SA-Exim-Connect-IP: 94.175.94.161 X-SA-Exim-Mail-From: broonie@sirena.org.uk Subject: Re: [PATCH] spi: core: Increase timeout value X-SA-Exim-Version: 4.2.1 (built Mon, 26 Dec 2011 16:24:06 +0000) X-SA-Exim-Scanned: Yes (on mezzanine.sirena.org.uk) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --DaTEgnRu5pEC8TLg Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Thu, Apr 10, 2014 at 06:20:29PM +0530, Harini Katakam wrote: > Considering acceptable latencies, this timeout can be set to a large > value >= 1*HZ typically. > This patch adds a tolerance of 2000 msec in the core accordingly. That's too much, it's 2 seconds which gets to be incredibly painful when trying to debug problems - if you're sitting there waiting for a driver to time out some operations (and it may be more than one of them) so you can look at the diagnostics it can be quite aggrivating. That's why the delays are related to the expected runtime for the operation. Something like double the expected runtime plus something in the 100ms or so range perhaps? Ideally we'd use the actual speed the device set rather than the requested one too, that'd help. --DaTEgnRu5pEC8TLg Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.22 (GNU/Linux) iQIcBAEBAgAGBQJTRtaNAAoJELSic+t+oim9LeEP/R9f6o0YW3zxWF++cgXl4c7D n/AM00SOyDaMIwXJjjX50/mrnWz1V3HEbhZY799FjhSAVvhS+nR15RlZROzvfet9 bIIQ+8WCHFh2YRAqWk+pUzdOu+3iswKZ+4upEWXedGOqwL8BS2KIXrANE4JSsoTQ 8nmj8ch7wm31E6gjZTI0ykSy3+p0DnLpYM5vnH2sZPIXLXj0OzyKmy9weLvrEb+7 VFnzusSk0mKn6mNQgxOvFdgYudZ6fHne1x6rGhiu4fn+22ziRoA0k+lPWfngiEkt z2xe9x9bQVbfTc9BcGI8E4FwggHtFqIULWYwXCivMuCFPP7n70UjS7sIwmv4ax7c nlWwG8HLc7V0osuJGdcpHM4l3dvZa8roBh+XPmfAH+aNJvvHrLskYM9RBEllxdln 9VMGm4LpZ+03FIAB++b2ij+hEIaoKu78XHkBZo1keqkU4QMV49s//XANdXaryRTL 8Es4Yz13cpNUh1DzB1Wigpz0dBX7n5FByrXJ4y06z3+bqd0GkCFeIXF0yAi8s+Dy vppFVzVtit/WBshSkn5ivuyi1nDI8yM9s3hBI++wEAnciLq0Ba2GIDQkRYLMho8A WiSRWoyUFGBi9zOgItNfkwrlEIzKfb68nibCEbOlxXBxKYraTsDlQg0YpEvdzOK/ X1RaPkQOnDlhfQOXO8ZF =8MsI -----END PGP SIGNATURE----- --DaTEgnRu5pEC8TLg-- From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark Brown Subject: Re: [PATCH] spi: core: Increase timeout value Date: Thu, 10 Apr 2014 18:36:16 +0100 Message-ID: <20140410173616.GC6518@sirena.org.uk> References: <1397134229-2380-1-git-send-email-harinik@xilinx.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="DaTEgnRu5pEC8TLg" Cc: linux-spi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, michals-gjFFaj9aHVfQT0dZR+AlfA@public.gmane.org To: Harini Katakam Return-path: Content-Disposition: inline In-Reply-To: <1397134229-2380-1-git-send-email-harinik-gjFFaj9aHVfQT0dZR+AlfA@public.gmane.org> Sender: linux-spi-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: --DaTEgnRu5pEC8TLg Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Thu, Apr 10, 2014 at 06:20:29PM +0530, Harini Katakam wrote: > Considering acceptable latencies, this timeout can be set to a large > value >= 1*HZ typically. > This patch adds a tolerance of 2000 msec in the core accordingly. That's too much, it's 2 seconds which gets to be incredibly painful when trying to debug problems - if you're sitting there waiting for a driver to time out some operations (and it may be more than one of them) so you can look at the diagnostics it can be quite aggrivating. That's why the delays are related to the expected runtime for the operation. Something like double the expected runtime plus something in the 100ms or so range perhaps? Ideally we'd use the actual speed the device set rather than the requested one too, that'd help. --DaTEgnRu5pEC8TLg Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.22 (GNU/Linux) iQIcBAEBAgAGBQJTRtaNAAoJELSic+t+oim9LeEP/R9f6o0YW3zxWF++cgXl4c7D n/AM00SOyDaMIwXJjjX50/mrnWz1V3HEbhZY799FjhSAVvhS+nR15RlZROzvfet9 bIIQ+8WCHFh2YRAqWk+pUzdOu+3iswKZ+4upEWXedGOqwL8BS2KIXrANE4JSsoTQ 8nmj8ch7wm31E6gjZTI0ykSy3+p0DnLpYM5vnH2sZPIXLXj0OzyKmy9weLvrEb+7 VFnzusSk0mKn6mNQgxOvFdgYudZ6fHne1x6rGhiu4fn+22ziRoA0k+lPWfngiEkt z2xe9x9bQVbfTc9BcGI8E4FwggHtFqIULWYwXCivMuCFPP7n70UjS7sIwmv4ax7c nlWwG8HLc7V0osuJGdcpHM4l3dvZa8roBh+XPmfAH+aNJvvHrLskYM9RBEllxdln 9VMGm4LpZ+03FIAB++b2ij+hEIaoKu78XHkBZo1keqkU4QMV49s//XANdXaryRTL 8Es4Yz13cpNUh1DzB1Wigpz0dBX7n5FByrXJ4y06z3+bqd0GkCFeIXF0yAi8s+Dy vppFVzVtit/WBshSkn5ivuyi1nDI8yM9s3hBI++wEAnciLq0Ba2GIDQkRYLMho8A WiSRWoyUFGBi9zOgItNfkwrlEIzKfb68nibCEbOlxXBxKYraTsDlQg0YpEvdzOK/ X1RaPkQOnDlhfQOXO8ZF =8MsI -----END PGP SIGNATURE----- --DaTEgnRu5pEC8TLg-- -- 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