From mboxrd@z Thu Jan 1 00:00:00 1970 From: Scott Wood Date: Fri, 18 May 2012 10:55:06 -0500 Subject: [U-Boot] [PATCH 2/2 v3] FSL/eSDHC: enable the clock to detect the SD card In-Reply-To: <1337335022-18501-2-git-send-email-Chang-Ming.Huang@freescale.com> References: <1337335022-18501-1-git-send-email-Chang-Ming.Huang@freescale.com> <1337335022-18501-2-git-send-email-Chang-Ming.Huang@freescale.com> Message-ID: <4FB670DA.4000304@freescale.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de On 05/18/2012 04:57 AM, Chang-Ming.Huang at freescale.com wrote: > From: Jerry Huang > > For FSL low-end processors (VVN2.2), in order to detect the SD card, > we should enable PEREN, HCKEN and IPGEN to enable the clock. > Otherwise, after booting the u-boot, and then inserting the SD card, > the SD card can't be detected. > For SDHC VVN2.3 IP, these bits are reserved, and SDCLKEN is used. > And when accessing to these reserved bit, no any impact happened. Again, have you talked to a hardware designer and confirmed that there's no impact from setting these bits on chips where they're reserved? Just because you don't notice any obvious impact doesn't mean it's totally safe. -Scott