Messages in this thread | | | From | Richard Genoud <> | Date | Thu, 16 Aug 2012 12:35:23 +0200 | Subject | Re: [PATCH 3/4] UBI: use the whole MTD device size to get bad_peb_limit |
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2012/8/16 Shmulik Ladkani <shmulik.ladkani@gmail.com>: > Hi Artem, Richard, > > On Wed, 15 Aug 2012 18:08:51 +0300 Artem Bityutskiy <dedekind1@gmail.com> wrote: >> 1. Invalid blocks are block that contain one or more bad bits beyond >> ECC. > > I would remove this one sentence from the log, it is misleading; invalid > blocks are not necessarily related to ECC. I agree (even if this sentence is from a nand datasheet !)
> >> if (CONFIG_MTD_UBI_BEB_LIMIT > 0) { >> - int percent = CONFIG_MTD_UBI_BEB_LIMIT; >> - int limit = mult_frac(ubi->peb_count, percent, 100); >> + int per1024 = CONFIG_MTD_UBI_BEB_LIMIT; >> + int limit, device_pebs; >> + uint64_t device_size; >> + >> + /* >> + * Here we are using size of the entire flash chip and >> + * not just the MTD partition size because the maximum >> + * number of bad eraseblocks is a percentage of the >> + * whole device and bad eraseblocks are not fairly >> + * distributed over the flash chip. So the worst case >> + * is that all the bad eraseblocks of the chip are in >> + * the MTD partition we are attaching (ubi->mtd). >> + */ >> + device_size = mtd_get_device_size(ubi->mtd); >> + device_pebs = mtd_div_by_eb(device_size, ubi->mtd); >> + limit = mult_frac(device_pebs, per1024, 1024); >> >> /* Round it up */ >> - if (mult_frac(limit, 100, percent) < ubi->peb_count) >> + if (mult_frac(limit, 1024, per1024) < ubi->peb_count) > > Oops... should be: > > + if (mult_frac(limit, 1024, per1024) < device_pebs) > > Regards, > Shmulik Ok, I'll change that, may be in a separate patch, as it's a bug fix. I'll add your signoff.
thanks !
-- for me, ck means con kolivas and not calvin klein... does it mean I'm a geek ?
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