| Message ID | 1387403050-23965-2-git-send-email-ezequiel.garcia@free-electrons.com |
|---|---|
| State | Superseded |
| Headers | show |
diff --git a/drivers/mtd/nand/pxa3xx_nand.c b/drivers/mtd/nand/pxa3xx_nand.c index 8f38abd..9828033 100644 --- a/drivers/mtd/nand/pxa3xx_nand.c +++ b/drivers/mtd/nand/pxa3xx_nand.c @@ -690,6 +690,7 @@ static void prepare_start_command(struct pxa3xx_nand_info *info, int command) info->retcode = ERR_NONE; info->ecc_err_cnt = 0; info->ndcb3 = 0; + info->need_wait = 0; switch (command) { case NAND_CMD_READ0:
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(+)