Messages in this thread | | | Subject | Re: [PATCH try #2] Blackfin on-chip NAND Flash Controller driver | From | Bryan Wu <> | Date | Tue, 11 Sep 2007 17:04:47 +0800 |
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On Tue, 2007-09-11 at 11:35 +0300, Artem Bityutskiy wrote: > Hi, > > On Mon, 2007-09-10 at 17:50 +0800, Bryan Wu wrote: > > Here is the test log, only 2 errors in oobtest. After digging into the > > mtd-nand driver code, it should be no relation to my bf5xx_nand driver. > > Maybe somethings wrong in the mtd-nand code. I intend to get some help > > from you, please see my test log below: > > > oobtest: Attempting to read past end of device > > oobtest: An error is expected... > > oobtest: error: read past end of device > > This means that MTD did not return an error when the test tried to read > the last NAND page's OOB. Here is the code: > > /* Attempt to write off end of device */ > ops.mode = MTD_OOB_AUTO; > ops.ooblen = mtd->ecclayout->oobavail + 1; > ops.oobbuf = writebuf; > printk(PRINT_PREF "Attempting to write past end of device\n"); > printk(PRINT_PREF "An error is expected...\n"); > err = mtd->write_oob(mtd, mtd->size - mtd->writesize, &ops); > > So we read OOB size + 1 byte from the last NAND page and get no error. >
Yes, it makes sense.
> This test passes for nandsim, so I'm not sure the problem is in the > generic code. On the other hand, it is generic code which should check > rages.
Actually, I debugged both oobtest.c and drivers/mtd/nand/nand_base.c
in the kernel nand_base.c mtd->read_oob() --> nand_read_oob() --> nand_do_read_oob() --> chip->ecc.read_oob() --> nand_read_oob_std() --> chip->read_buf() --> bf5xx_nand.c bf5xx_nand_dma_read_buf().
In the calling path, rage check should not be in my driver code bf5xx_nand_dma_read_buf() like other low level nand controller drivers. It is already in nand_do_read_oob() as below:
--- /* Do not allow reads past end of device */ if (unlikely(from >= mtd->size || ops->ooboffs + readlen > ((mtd->size >> chip->page_shift) - (from >> chip->page_shift)) * len)) { DEBUG(MTD_DEBUG_LEVEL0, "nand_read_oob: " "Attempt read beyond end of device\n"); return -EINVAL; } ---
maybe this condition testing does not include your case. I am not sure, still busy at other task.
> > oobtest: Attempting to write past end of device > > oobtest: An error is expected... > > nand_write_oob: Attempt to write past end of page > > oobtest: Error occurred as expected > > oobtest: Attempting to read past end of device > > oobtest: An error is expected... > > oobtest: error: read past end of device > > Similar. > > > I plan to do the torture test after this oobtest passed. And this > > nand_test suites are intended to integrated into our Blackfin > > uClinux-dist testsuites. > > We are planning to clean up the tests and submit them for kernel > inclusion some day, when we have time. >
Good news. Thanks Best Regards, - Bryan Wu
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