From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wolfram Sang Subject: Re: [PATCH] mmc: core: Remove timeout when enabling cache Date: Tue, 20 Nov 2018 11:23:01 +0100 Message-ID: <20181120102300.GA1056@kunai> References: <20181106133007.12318-1-sjoerd.simons@collabora.co.uk> <9051c212-6e2a-bc39-3686-693e6cd87f1d@ti.com> <303b49cbb5b687d6b6a7ad4048eda459586c0806.camel@collabora.co.uk> <20181107084741.GA31092@kunai> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="GvXjxJ+pjyke8COw" Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org To: Ulf Hansson Cc: Faiz Abbas , Sjoerd Simons , "linux-mmc@vger.kernel.org" , kernel@collabora.com, Linux Kernel Mailing List , Hongjie Fang , Bastian Stender , Kyle Roeschley , Wolfram Sang , Shawn Lin , Harish Jenny K N , Simon Horman List-Id: linux-mmc@vger.kernel.org --GvXjxJ+pjyke8COw Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable > >> That also happens to be one of the cards we deploy; However i did > >> wonder about adding a quirk but decided against it as it was not clear > >> to me from the specification that CACHE ON really is meant to complete > >> within GENERIC_CMD6_TIMEOUT. That and i fret about ending up in hit-a- > >> mole games as the failure is really quite tedious (boot failure). > > > > I agree that we should use the more defensive variant as a default. I > > mean there should be no performance regression since most cards will > > respond just faster, or? The only downside I could see is that we might > > miss a real timeout with no bounds set and might get stuck? >=20 > Well, you have a point, but still it's kind of nice to know which > cards are behaving well and which ones that doesn't. Hence I think I > prefer to stick using a quirk, unless you have a strong opinion. No strong opinion. Especially not if you say it is in the spec (although "must be sufficient" would be better than "should be" ;)). Also, I assume this failure is reproducible and should turn up during development? Compared to "happens once in a while randomly"? Yet, if we add a quirk for that, then we should probably mention it in an error message when we hit -ETIMEDOUT for cache on ("does your card need this quirk?")? It can be pretty time consuming to track this down otherwise, I'd think. --GvXjxJ+pjyke8COw Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEOZGx6rniZ1Gk92RdFA3kzBSgKbYFAlvz4IAACgkQFA3kzBSg KbYtPRAAlmLJPEorqqLLfPi7QvqV88+05ctnsL3aV/EqztKbRgQ/DjlDHmYpXozm WjRTG8HyRCLAlXQ6xC2TYQw+uqT0FzsOnzEVLtk8vsgfOjw0LOUhnAN5nJnc4jLl h3w3FGD71XH7cvM3QE4mCacYaiGLPVWpSbnDbTiPP9ljHlQpNPoVMlzgUxlDz6Gi eVNsT/r/PKboxBEdTox96bXxuGS8p0caV6p1yyFzROEf0+iyXEyQ16AjMhU4xMh8 ZwmpkUslSfzqPy9Ird5tYEvbAF7k9d5lDO1Lu0fxKa8YjxKR4kh3sNP/5jQ1lQvF 7qHYDi8UmOJG/9M+4KuqDsi4vVp9+H4apv98HRjlpHws+jeXPOBo9/iFLUthJyQ/ Uf+Yn7Hw74oH8PA3VFy/+j+eChPxJ4Fbz5dZ+d35L5Q3Q5+9nta9ZPEaXFoq3p6G 5twl0T+9v0QXdGp1zajSuquS40h7g7/vZOmded/CGHdSUiN5lI2/utGeKHK3wnVP SyZsEETFUf+3zcAPPrH7MI6qL1lBpVOxU6kDyGtS5mu8Bg6RMbKfNXqO+3Kyn+5P xenwy4w1ptTrsQyVsV5pSLHgTA/GmMB2fSvFZTgyJAvpv2hZvWRCeD3aX7FhB/0O CscRQHUlYB5hitEOnb+scm6qwH5hP0cBZSVsFb7lPfkh60BftLc= =Hkb8 -----END PGP SIGNATURE----- --GvXjxJ+pjyke8COw--