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51 lines
1.8 KiB
Diff
51 lines
1.8 KiB
Diff
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From 7efaa8677ffd07d54d0122b5e92f29b74a36ad39 Mon Sep 17 00:00:00 2001
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From: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
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Date: Thu, 19 Dec 2013 06:08:03 -0300
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Subject: [PATCH 162/203] mtd: nand: pxa3xx: Clear need_wait flag when starting
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a command
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Currently the driver assumes all commands will eventually trigger a RnB
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transition, and thus a "device is ready" IRQ.
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This assumption means that on every issued command, the dev_ready completion
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handler is init'ed and the need_wait flag is set.
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However this is incorrect: some commands (such as NAND_CMD_STATUS) don't
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make the device 'busy' and thus a RnB transition never occurs.
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Given, the NAND core never calls waitfunc() after such commands, this
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is not a problem.
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Therefore, it's possible to only clear the need_wait flag on every command
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that is started.
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This fixes a current bug that can be reproduced on PXA boards by writing
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blank (all 0xff'ed) to a page:
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1. The kernel issues NAND_CMD_STATUS and sets need_wait=1. The flag
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won't be cleared for this command since no RnB transition is
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involved.
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2. NAND_CMD_PAGEPROG is issued but since the data is blank, the driver
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decides not to execute the command (and no IRQ activity is
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involved).
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3. The NAND core calls waitfunc() and waits for the dev_ready
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completion, which will never end since the device _is_ already ready.
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Tested-by: Arnaud Ebalard <arno@natisbad.org>
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Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
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---
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drivers/mtd/nand/pxa3xx_nand.c | 1 +
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1 file changed, 1 insertion(+)
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--- a/drivers/mtd/nand/pxa3xx_nand.c
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+++ b/drivers/mtd/nand/pxa3xx_nand.c
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@@ -694,6 +694,7 @@ static void prepare_start_command(struct
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info->retcode = ERR_NONE;
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info->ecc_err_cnt = 0;
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info->ndcb3 = 0;
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+ info->need_wait = 0;
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switch (command) {
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case NAND_CMD_READ0:
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