From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tony Lindgren Subject: Re: [PATCH] ARM: OMAP: MMC performance upgrade on OMAP2 Date: Thu, 29 Mar 2007 16:13:18 -0400 Message-ID: <20070329201316.GG3638@atomide.com> References: <00e501c7608c$6ec71fe0$c7a3580a@swcenter.sec.samsung.co.kr> <9C23CDD79DA20A479D4615857B2E2C476F2884@dlee13.ent.ti.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <9C23CDD79DA20A479D4615857B2E2C476F2884@dlee13.ent.ti.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-omap-open-source-bounces@linux.omap.com Errors-To: linux-omap-open-source-bounces@linux.omap.com To: "Syed Mohammed, Khasim" Cc: linux-omap-open-source@linux.omap.com, kmpark@infradead.org List-Id: linux-omap@vger.kernel.org Hi, * Syed Mohammed, Khasim [070308 23:38]: > Hi Kyungmin, > > For OMAP2420 there are few MMC erratas, > > 1. If MMC controller is configured for 4bit and if MMC CLK frequency is > over 24Mhz it has as a diminishing impact on throughput. Hence, it is > not recommended to use a clock over 24MHz for MMC 4 bits mode. > >@@ -1096,7 +1098,10 @@ static int __init mmc_omap_probe(struct > >platform_device *pdev) > > > > mmc->ops = &mmc_omap_ops; > > mmc->f_min = 400000; > >- mmc->f_max = 24000000; > >+ if (cpu_class_is_omap2()) > >+ mmc->f_max = 48000000; > >+ else > >+ mmc->f_max = 24000000; > > mmc->ocr_avail = MMC_VDD_32_33 | MMC_VDD_33_34; > > mmc->caps = MMC_CAP_MULTIWRITE | MMC_CAP_BYTEBLOCK; How about throwing a cpu_is_omap2420() in there to work around the clock limitation above mentioned by Khasim? Tony