diff options
Diffstat (limited to 'target/linux/mvebu/patches-3.10/0162-mtd-nand-pxa3xx-Clear-need_wait-flag-when-starting-a.patch')
| -rw-r--r-- | target/linux/mvebu/patches-3.10/0162-mtd-nand-pxa3xx-Clear-need_wait-flag-when-starting-a.patch | 50 |
1 files changed, 50 insertions, 0 deletions
diff --git a/target/linux/mvebu/patches-3.10/0162-mtd-nand-pxa3xx-Clear-need_wait-flag-when-starting-a.patch b/target/linux/mvebu/patches-3.10/0162-mtd-nand-pxa3xx-Clear-need_wait-flag-when-starting-a.patch new file mode 100644 index 0000000000..5665ca13e6 --- /dev/null +++ b/target/linux/mvebu/patches-3.10/0162-mtd-nand-pxa3xx-Clear-need_wait-flag-when-starting-a.patch @@ -0,0 +1,50 @@ +From 7efaa8677ffd07d54d0122b5e92f29b74a36ad39 Mon Sep 17 00:00:00 2001 +From: Ezequiel Garcia <ezequiel.garcia@free-electrons.com> +Date: Thu, 19 Dec 2013 06:08:03 -0300 +Subject: [PATCH 162/203] mtd: nand: pxa3xx: Clear need_wait flag when starting + a command + +Currently the driver assumes all commands will eventually trigger a RnB +transition, and thus a "device is ready" IRQ. + +This assumption means that on every issued command, the dev_ready completion +handler is init'ed and the need_wait flag is set. + +However this is incorrect: some commands (such as NAND_CMD_STATUS) don't +make the device 'busy' and thus a RnB transition never occurs. +Given, the NAND core never calls waitfunc() after such commands, this +is not a problem. + +Therefore, it's possible to only clear the need_wait flag on every command +that is started. + +This fixes a current bug that can be reproduced on PXA boards by writing +blank (all 0xff'ed) to a page: + + 1. The kernel issues NAND_CMD_STATUS and sets need_wait=1. The flag + won't be cleared for this command since no RnB transition is + involved. + + 2. NAND_CMD_PAGEPROG is issued but since the data is blank, the driver + decides not to execute the command (and no IRQ activity is + involved). + + 3. The NAND core calls waitfunc() and waits for the dev_ready + completion, which will never end since the device _is_ already ready. + +Tested-by: Arnaud Ebalard <arno@natisbad.org> +Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com> +--- + drivers/mtd/nand/pxa3xx_nand.c | 1 + + 1 file changed, 1 insertion(+) + +--- a/drivers/mtd/nand/pxa3xx_nand.c ++++ b/drivers/mtd/nand/pxa3xx_nand.c +@@ -694,6 +694,7 @@ static void prepare_start_command(struct + info->retcode = ERR_NONE; + info->ecc_err_cnt = 0; + info->ndcb3 = 0; ++ info->need_wait = 0; + + switch (command) { + case NAND_CMD_READ0: |