From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arnd Bergmann Subject: Re: [PATCH v4 2/3]mmc: enable TRIM/ERASE caps for SDHCI host Date: Sat, 12 Feb 2011 09:34:04 +0100 Message-ID: <201102120934.04679.arnd@arndb.de> References: <20110212062220.GC25519@intel.com> Mime-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Return-path: Received: from moutng.kundenserver.de ([212.227.126.171]:62263 "EHLO moutng.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751801Ab1BLIeQ (ORCPT ); Sat, 12 Feb 2011 03:34:16 -0500 In-Reply-To: <20110212062220.GC25519@intel.com> Sender: linux-mmc-owner@vger.kernel.org List-Id: linux-mmc@vger.kernel.org To: Chuanxiao Dong Cc: linux-mmc@vger.kernel.org, cjb@laptop.org, linux-kernel@vger.kernel.org, akpm@linux-foundation.org, adrian.hunter@nokia.com On Saturday 12 February 2011 07:22:20 Chuanxiao Dong wrote: > SDHCI host controller has TRIM/ERASE capability, enable these caps for erasing > purpose. > > ERASE command needs R1B response. So for such command with busy signal, before > sending command, SDHCI host driver will simply set a maximum value for timeout > control register which is safe to use. > > Signed-off-by: Chuanxiao Dong Great stuff! I needed this for a project of mine, but couldn't get it to work reliably without knowing about the timeout logic. I think, almost no mmc controllers advertice MMC_CAP_ERASE today, which is a real shame, given that it's extremely useful for performance. Arnd