From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alan Cox Subject: Re: Compact Flash Question Date: Tue, 6 May 2008 23:09:54 +0100 Message-ID: <20080506230954.6e034cba@core> References: <005b01c8afc4$77f4ec90$6401a8c0@techwriter> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: Received: from outpipe-village-512-1.bc.nu ([81.2.110.250]:56117 "EHLO lxorguk.ukuu.org.uk" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1751379AbYEFWT3 (ORCPT ); Tue, 6 May 2008 18:19:29 -0400 In-Reply-To: <005b01c8afc4$77f4ec90$6401a8c0@techwriter> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Yigal Sadgat Cc: linux-kernel@vger.kernel.org, linux-ide@vger.kernel.org, jwboyer@linux.vnet.ibm.com, joern@logfs.org > (1) Can you really ignore bit(2) (CORR) in the Status register offset 7 that > tells > you that the CF has detected and corrected a soft error?, etc. I guess it might be interesting to log the error rate but we don't currently do that. A corrected error is just that however - corrected by the card itself. > (2) An engineer at SanDisk Engineering told me NOT to do wear leveling. > The file allocation table is written very frequently back into the flash. So > is it really safe to assume that I don't need wear leveling??? Depends on your hardware vendor. Wear management is done within the CF card and only the hardware vendor can tell you what they do. > (3) Re. the BUSY bit in the status register (offset 7, bit D7), anybody > experienced > time outs? Yes - both from failing CF cards and also other random events (bad connections, people removing live cards etc) > (4) Re Error register (offset 1) bit D7 (BBK), again, I was told that it > cannot (???) > happen since the CF performs read-after-write and it automatically switches > good blocks > for bad ones... Is this correct? Depends on your hardware vendor. It certainly *can* occur with some CF cards perhaps when they run out of spare blocks. Alan