From: Ofer Heifetz oferh@marvell.com
When 2 commands are submitted in a row, and the second is very quick, the completion of the second command might never come. This happens especially if the second command is quick, such as a status read after an erase
[ Linux commit 21fc0ef9652f0c809dc0d3e0a67f1e1bf6ff8255 ]
Cc: Robert Jarzmik <robert.jarzmik at free.fr> Signed-off-by: Chris Packham <judge.packham at gmail.com> Reviewed-by: Ofer Heifetz oferh@marvell.com Tested-by: Ofer Heifetz oferh@marvell.com --- drivers/mtd/nand/pxa3xx_nand.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-)
diff --git a/drivers/mtd/nand/pxa3xx_nand.c b/drivers/mtd/nand/pxa3xx_nand.c index 5d37f22..d83efea 100644 --- a/drivers/mtd/nand/pxa3xx_nand.c +++ b/drivers/mtd/nand/pxa3xx_nand.c @@ -624,8 +624,14 @@ static irqreturn_t pxa3xx_nand_irq(struct pxa3xx_nand_info *info) is_ready = 1; }
+ /* + * Clear all status bit before issuing the next command, which + * can and will alter the status bits and will deserve a new + * interrupt on its own. This lets the controller exit the IRQ + */ + nand_writel(info, NDSR, status); + if (status & NDSR_WRCMDREQ) { - nand_writel(info, NDSR, NDSR_WRCMDREQ); status &= ~NDSR_WRCMDREQ; info->state = STATE_CMD_HANDLE;
@@ -646,8 +652,6 @@ static irqreturn_t pxa3xx_nand_irq(struct pxa3xx_nand_info *info) nand_writel(info, NDCB0, info->ndcb3); }
- /* clear NDSR to let the controller exit the IRQ */ - nand_writel(info, NDSR, status); if (is_completed) info->cmd_complete = 1; if (is_ready)