| Message ID | 1325647126-4281-1-git-send-email-b32955@freescale.com |
|---|---|
| State | New, archived |
| Headers | show |
On Wed, 2012-01-04 at 11:18 +0800, Huang Shijie wrote: > In MX28, if we do not reset the BCH module. The BCH module may > becomes unstable when the board reboots for several thousands times. > This bug has been catched in customer's production. > > The patch adds some comments(some from Wolfram Sang), and fixes it now. > > Also change gpmi_reset_block() to static. > > Signed-off-by: Huang Shijie <b32955@freescale.com> > Acked-by: Marek Vasut <marek.vasut@gmail.com> Pushed to l2-mtd-2.6.git, thanks!
On Tue, Jan 10, 2012 at 10:49:00AM +0200, Artem Bityutskiy wrote: > On Wed, 2012-01-04 at 11:18 +0800, Huang Shijie wrote: > > In MX28, if we do not reset the BCH module. The BCH module may > > becomes unstable when the board reboots for several thousands times. > > This bug has been catched in customer's production. > > > > The patch adds some comments(some from Wolfram Sang), and fixes it now. > > > > Also change gpmi_reset_block() to static. > > > > Signed-off-by: Huang Shijie <b32955@freescale.com> > > Acked-by: Marek Vasut <marek.vasut@gmail.com> > > Pushed to l2-mtd-2.6.git, thanks! I somehow missed this patch, if it's not too late, you can add my Reviewed-by: Wolfram Sang <w.sang@pengutronix.de>
On Wed, 2012-01-11 at 11:43 +0100, Wolfram Sang wrote: > > Pushed to l2-mtd-2.6.git, thanks! > > I somehow missed this patch, if it's not too late, you can add my > > Reviewed-by: Wolfram Sang <w.sang@pengutronix.de> Sorry, it is upstream already.
diff --git a/drivers/mtd/nand/gpmi-nand/gpmi-lib.c b/drivers/mtd/nand/gpmi-nand/gpmi-lib.c index de4db76..7523691 100644 --- a/drivers/mtd/nand/gpmi-nand/gpmi-lib.c +++ b/drivers/mtd/nand/gpmi-nand/gpmi-lib.c @@ -69,17 +69,19 @@ static int clear_poll_bit(void __iomem *addr, u32 mask) * [1] enable the module. * [2] reset the module. * - * In most of the cases, it's ok. But there is a hardware bug in the BCH block. + * In most of the cases, it's ok. + * But in MX23, there is a hardware bug in the BCH block(see 2847 from errata). * If you try to soft reset the BCH block, it becomes unusable until * the next hard reset. This case occurs in the NAND boot mode. When the board * boots by NAND, the ROM of the chip will initialize the BCH blocks itself. * So If the driver tries to reset the BCH again, the BCH will not work anymore. - * You will see a DMA timeout in this case. + * You will see a DMA timeout in this case. The bug has been fixed + * in the following chips, such as MX28. * * To avoid this bug, just add a new parameter `just_enable` for * the mxs_reset_block(), and rewrite it here. */ -int gpmi_reset_block(void __iomem *reset_addr, bool just_enable) +static int gpmi_reset_block(void __iomem *reset_addr, bool just_enable) { int ret; int timeout = 0x400; @@ -206,7 +208,15 @@ int bch_set_geometry(struct gpmi_nand_data *this) if (ret) goto err_out; - ret = gpmi_reset_block(r->bch_regs, true); + /* + * Due to Errata #2847 of the MX23, the BCH cannot be soft reset on this + * chip, otherwise it will lock up. So we skip resetting BCH on the MX23. + * On the other hand, the MX28 needs the reset, because one case has been + * seen where the BCH produced ECC errors constantly after 10000 + * consecutive reboots. The latter case has not been seen on the MX23 yet, + * still we don't know if it could happen there as well. + */ + ret = gpmi_reset_block(r->bch_regs, GPMI_IS_MX23(this)); if (ret) goto err_out;