From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Yigal Sadgat" Subject: Compact Flash Question Date: Tue, 6 May 2008 14:59:33 -0700 Message-ID: <005b01c8afc4$77f4ec90$6401a8c0@techwriter> Mime-Version: 1.0 Content-Type: text/plain; format=flowed; charset="iso-8859-1"; reply-type=original Content-Transfer-Encoding: 7bit Return-path: Received: from cdptpa-omtalb.mail.rr.com ([75.180.132.121]:57796 "EHLO cdptpa-omtalb.mail.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753765AbYEFV7p (ORCPT ); Tue, 6 May 2008 17:59:45 -0400 Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: linux-kernel@vger.kernel.org, linux-ide@vger.kernel.org Cc: jwboyer@linux.vnet.ibm.com, joern@logfs.org We wrote the Kernel to support CF drives (in IDE mode) several years ago but now there are strange things coming back from the field that compel us to go back and re-evaluate many design decisions. For instance, (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. (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??? (3) Re. the BUSY bit in the status register (offset 7, bit D7), anybody experienced time outs? (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? We get many "soft" errors and I cannot wait to put my hand on a system to test but thought I would draw on your collective experience before we dive into these issues again. Any comments would be greatly appreciated. Yigal Sadgat General Computer Technology (GCT) YSadgat1@gcte.com