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From: Timur Tabi <timur@freescale.com>
To: u-boot@lists.denx.de
Subject: [U-Boot-Users] [PATCH] Fixed cfi flash read uchar bug.
Date: Thu, 25 Jan 2007 10:10:18 -0600	[thread overview]
Message-ID: <45B8D66A.6080209@freescale.com> (raw)
In-Reply-To: <46B96294322F7D458F9648B60E15112C082EB6@zch01exm26.fsl.freescale.net>

Zhang Wei-r63237 wrote:
> Hi, Wolfgang,
> 
> It's so pity that the flash got wrong 'num_erase_regions' issue is still
> in u-boot 1.2.0.
> 
> The byte by byte accessing is not preferred. But the flash_read_ushort()
> and flash_read_long() in drivers/cfi_flash.c are both implemented by
> byte accessing. How about it?
> 
> Can the instruction '
> 	retval = (addr[0] << 16) | (addr[(info->portwidth)] << 24) |
> 		(addr[(2 * info->portwidth)]) | (addr[(3 *
> info->portwidth)] << 8);'
> In flash_read_long() be replaced by memcpy() function?

I really don't think we should be using mempcy().  You're not supposed 
to care about the internal implementation of mempcy(), so if we start 
using it for specific-sized reads, then we start caring about how it's 
implemented.

If you want to read 32 bits at one time, then just do a 32-bit read!

	retval = * (ulong *) addr;

Looking at the code, I don't understand why it's so complicated.  If 
portwidth is 2, then retval above will be a conglomeration of addr[0], 
addr[2], addr[4], and addr[6].  Why isn't it just reading from 
[0][1][2][3]??

  reply	other threads:[~2007-01-25 16:10 UTC|newest]

Thread overview: 55+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2006-12-22  7:27 [U-Boot-Users] [PATCH] Fixed cfi flash read uchar bug wei.zhang at freescale.com
2006-12-22 10:00 ` Wolfgang Denk
2006-12-22 11:02   ` Zhang Wei
2006-12-22 14:11     ` Wolfgang Denk
2006-12-22 16:34       ` [U-Boot-Users] 答复: " Zhang Wei-r63237
2006-12-22 17:17         ` Wolfgang Denk
2006-12-25  7:03           ` Zhang Wei
2006-12-25 23:24             ` Wolfgang Denk
2006-12-26  6:04               ` Zhang Wei
2007-01-04  2:07                 ` Zhang Wei-r63237
2007-01-04  8:17                   ` Wolfgang Denk
2007-01-04  8:36               ` Zhang Wei-r63237
2007-01-04  9:23                 ` Wolfgang Denk
2007-01-04 11:19                   ` Stefan Roese
2007-01-05 13:27                   ` Stefan Roese
2007-01-07 10:12                     ` Tolunay Orkun
2007-01-07 10:40                       ` Wolfgang Denk
2007-01-13  7:11                         ` Tolunay Orkun
2007-01-13 17:53                           ` Håvard Skinnemoen
2007-01-16  6:52                             ` Stefan Roese
2007-01-25  4:38                           ` Zhang Wei-r63237
2007-01-25 16:10                             ` Timur Tabi [this message]
2007-01-25 20:33                               ` Wolfgang Denk
2007-01-26  2:13                                 ` Zhang Wei-r63237
2007-01-29 11:29                                   ` Tolunay Orkun
2007-01-30  3:36                                     ` Wang Haiying-r54964
2007-01-31  9:01                                       ` Tolunay Orkun
2007-01-31 19:25                                         ` Haiying Wang
2007-02-01  5:26                                           ` Tolunay Orkun
2007-02-01 22:06                                             ` Haiying Wang
2007-02-01 22:52                                               ` Chris Fester
2007-02-09 17:47                                             ` [U-Boot-Users] [PATCH0/2] Re-do the patch for adding DO_SYNC in flash_write_cmd Haiying Wang
2007-02-09 19:42                                               ` Wolfgang Denk
2007-02-09 19:48                                                 ` Haiying Wang
2007-02-10  1:04                                                   ` Wolfgang Denk
2007-02-10  7:23                                                     ` Tolunay Orkun
2007-02-10  7:40                                                       ` Stefan Roese
2007-02-10  7:57                                                         ` Tolunay Orkun
2007-02-10  8:07                                                           ` Stefan Roese
2007-02-10 21:55                                                             ` Wolfgang Denk
2007-02-10 21:54                                                         ` Wolfgang Denk
2007-02-11  2:34                                                         ` Timur Tabi
2007-02-11 10:23                                                           ` Wolfgang Denk
2007-02-09 19:59                                                 ` Haavard Skinnemoen
2007-02-10  1:02                                                   ` Wolfgang Denk
2007-02-09 17:47                                             ` [U-Boot-Users] [PATCH 1/2] Add DO_SYNC at the end of flash_write_cmd Haiying Wang
2007-02-09 19:45                                               ` Wolfgang Denk
2007-02-09 17:47                                             ` [U-Boot-Users] [PATCH 2/2] Define DO_SYNC in each CPU's header file Haiying Wang
2007-02-09 19:46                                               ` Wolfgang Denk
2007-02-10  7:17                                                 ` Tolunay Orkun
2007-01-08  2:41                     ` [U-Boot-Users] [PATCH] Fixed cfi flash read uchar bug Zhang Wei-r63237
2006-12-22 17:07       ` Chris Fester
2006-12-22 17:24         ` Wolfgang Denk
2006-12-22 17:42           ` Chris Fester
2006-12-22 21:33             ` Wolfgang Denk

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