From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mike Dunn Date: Tue, 09 Apr 2013 08:36:41 -0700 Subject: [U-Boot] [PATCH 7/8] mtd: nand: add driver for diskonchip g4 nand flash In-Reply-To: <1365469141.28843.31@snotra> References: <1365469141.28843.31@snotra> Message-ID: <51643589.70800@newsguy.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 04/08/2013 05:59 PM, Scott Wood wrote: > On 04/08/2013 01:25:01 AM, Marek Vasut wrote: >> Dear Mike Dunn, >> >> > This patch adds a driver for the diskonchip G4 nand flash device. It is >> > based on the driver from the linux kernel. >> > >> > This also includes a separate SPL driver. A separate SPL driver is used >> > because the device operates in a different mode (reliable mode) when >> > loading a boot image, and also because the storage format of the boot >> > image is different from normal data (pages are stored redundantly). The >> > SPL driver basically mimics how a typical IPL reads data from the device. >> > The special operating mode and storage format are used to compensate for >> > the fact that the IPL does not contain the BCH ecc decoding algorithm (due >> > to size constraints). Although the u-boot SPL *could* use ecc, it >> > operates like an IPL for the sake of simplicity and uniformity, since the >> > IPL and SPL share the task of loading the u-boot image. As a side benefit, >> > the SPL driver is very small. >> > >> > Signed-off-by: Mike Dunn >> >> Try #ifdef U_BOOT instead of #if 0, no? > > Just remove the code that would be hidden by #if 0. Besides making the U-Boot > code easier to read, we *want* to get a conflict marker if we try to merge in a > new upstream version, and those lines were changed in Linux. This would give us > an opportunity to see if similar changes are needed to the U-Boot version of the > code. OK. > > Another option would be to introduce for_each_set_bit in U-Boot. This was my first inclination, but it looked like a lot of work across multiple architectures, so I let it go. Thanks, Mike