[PATCH] ubi: Reject MLC NAND

While UBI and UBIFS seem to work at first sight with MLC NAND, you will most likely lose all your data upon a power-cut or due to read/write disturb. In order to protect users from bad surprises, refuse to attach to MLC NAND. Cc: sta...@vger.kernel.org Signed-off-by: Richard Weinberger --- drive

Re: [PATCH] ubi: Reject MLC NAND

On Sat 2018-03-03 11:45:54, Richard Weinberger wrote: > While UBI and UBIFS seem to work at first sight with MLC NAND, you will > most likely lose all your data upon a power-cut or due to read/write > disturb. > In order to protect users from bad surprises, refuse to attach to MLC > NAND. > > Cc:

Re: [PATCH] ubi: Reject MLC NAND

On 03/07/2018 12:18 AM, Pavel Machek wrote: > Now... Yes, handling flash is hard, MLC NAND is worst of the > bunch. But... > MLC is not just more flimsy than SLC NAND. The real problem is that on MLC NAND, pages come in pairs. Multiple voltage levels inside a single, physical memory cell are use

Re: [PATCH] ubi: Reject MLC NAND

Pavel, Am Mittwoch, 7. März 2018, 00:18:05 CET schrieb Pavel Machek: > On Sat 2018-03-03 11:45:54, Richard Weinberger wrote: > > While UBI and UBIFS seem to work at first sight with MLC NAND, you will > > most likely lose all your data upon a power-cut or due to read/write > > disturb. > > In orde

Re: [PATCH] ubi: Reject MLC NAND

On Wed, 2018-03-07 at 09:01 +0100, Richard Weinberger wrote: > Pavel, > > Am Mittwoch, 7. März 2018, 00:18:05 CET schrieb Pavel Machek: > > On Sat 2018-03-03 11:45:54, Richard Weinberger wrote: > > > While UBI and UBIFS seem to work at first sight with MLC NAND, > > > you will > > > most likely lo

Re: [PATCH] ubi: Reject MLC NAND

On Wed 2018-03-07 09:01:16, Richard Weinberger wrote: > Pavel, > > Am Mittwoch, 7. März 2018, 00:18:05 CET schrieb Pavel Machek: > > On Sat 2018-03-03 11:45:54, Richard Weinberger wrote: > > > While UBI and UBIFS seem to work at first sight with MLC NAND, you will > > > most likely lose all your d

Re: [PATCH] ubi: Reject MLC NAND

Hi Pavel, On Wed, Mar 7, 2018 at 1:43 PM, Pavel Machek wrote: > On Wed 2018-03-07 09:01:16, Richard Weinberger wrote: >> Pavel, >> >> Am Mittwoch, 7. März 2018, 00:18:05 CET schrieb Pavel Machek: >> > On Sat 2018-03-03 11:45:54, Richard Weinberger wrote: >> > > While UBI and UBIFS seem to work at

Re: [PATCH] ubi: Reject MLC NAND

On Wed, 2018-03-07 at 14:08 -0800, Steve deRosier wrote: > > To clarify one thing: the reason for this is MLC has actually never > been supported, nor worked properly. The fact that it kinda worked was > incidental and the cause of major problems for people due to that not > being clear. This pa

Re: [PATCH] ubi: Reject MLC NAND

On Wed 2018-03-07 22:11:13, David Woodhouse wrote: > > > On Wed, 2018-03-07 at 14:08 -0800, Steve deRosier wrote: > > > > To clarify one thing: the reason for this is MLC has actually never > > been supported, nor worked properly. The fact that it kinda worked was > > incidental and the cause of

Re: [PATCH] ubi: Reject MLC NAND

Hi Pavel, On Wed, 7 Mar 2018 23:17:33 +0100 Pavel Machek wrote: > On Wed 2018-03-07 22:11:13, David Woodhouse wrote: > > > > > > On Wed, 2018-03-07 at 14:08 -0800, Steve deRosier wrote: > > > > > > To clarify one thing: the reason for this is MLC has actually never > > > been supported, nor

Re: [PATCH] ubi: Reject MLC NAND

On Wed, 7 Mar 2018 22:43:42 +0100 Pavel Machek wrote: > On Wed 2018-03-07 09:01:16, Richard Weinberger wrote: > > Pavel, > > > > Am Mittwoch, 7. März 2018, 00:18:05 CET schrieb Pavel Machek: > > > On Sat 2018-03-03 11:45:54, Richard Weinberger wrote: > > > > While UBI and UBIFS seem to work

Re: [PATCH] ubi: Reject MLC NAND

Hi Boris, On Wed, Mar 07, 2018 at 11:30:57PM +0100, Boris Brezillon wrote: > I have one simple question: did you ever play with MLC NANDs or are you > just trolling? If you had, like Richard and I did when working on MLC > support, I'm pretty sure you wouldn't play this "don't backport to > stable

Re: [PATCH] ubi: Reject MLC NAND

On Sat, Mar 3, 2018 at 11:45 AM, Richard Weinberger wrote: > While UBI and UBIFS seem to work at first sight with MLC NAND, you will > most likely lose all your data upon a power-cut or due to read/write > disturb. > > In order to protect users from bad surprises, refuse to attach to MLC > NAND.

Re: [PATCH] ubi: Reject MLC NAND

Linus, Am Donnerstag, 8. März 2018, 14:42:16 CET schrieb Linus Walleij: > On Sat, Mar 3, 2018 at 11:45 AM, Richard Weinberger wrote: > > While UBI and UBIFS seem to work at first sight with MLC NAND, you will > > most likely lose all your data upon a power-cut or due to read/write > > disturb. >

Re: [PATCH] ubi: Reject MLC NAND

On Thu, 2018-03-08 at 15:43 +0100, Richard Weinberger wrote: > As stated by David Woodhouse, it was a huge mistake by UBI to not > reject MLC > NAND from the very beginning. Correction: when we were developing UBI/UBIFS and upstreamed them, MLC was widely used yet we did not really know about it.

Re: [PATCH] ubi: Reject MLC NAND

Artem, Am Donnerstag, 8. März 2018, 16:01:15 CET schrieb Artem Bityutskiy: > On Thu, 2018-03-08 at 15:43 +0100, Richard Weinberger wrote: > > As stated by David Woodhouse, it was a huge mistake by UBI to not > > reject MLC > > NAND from the very beginning. > > Correction: when we were developing

Re: [PATCH] ubi: Reject MLC NAND

On Thu, 2018-03-08 at 16:28 +0100, Richard Weinberger wrote: > You mean *not* widely used? Yes, indeed, thanks for correction. MLC just wasn't there yet when UBI/UBIFS were upstreamed.

Re: [PATCH] ubi: Reject MLC NAND

On Sat, 3 Mar 2018 11:45:54 +0100 Richard Weinberger wrote: > While UBI and UBIFS seem to work at first sight with MLC NAND, you will > most likely lose all your data upon a power-cut or due to read/write > disturb. > In order to protect users from bad surprises, refuse to attach to MLC > NAND.