Re: Spurious ECC errors with mtd_subpagetest (OMAP3, NAND)

2012-03-05 Thread Orjan Friberg
on the volatile-ness of NAND ECC errors? I.e., are they expected to be more persistent? Thanks, Orjan -- Orjan Friberg FlatFrog Laboratories AB -- To unsubscribe from this list: send the line unsubscribe linux-omap in the body of a message to majord...@vger.kernel.org More majordomo info at http

Re: Spurious ECC errors with mtd_subpagetest (OMAP3, NAND)

2012-03-05 Thread Orjan Friberg
looking at the BCH 4-bit code (both generic implementations and the OMAP GPMC-enabled one) in u-boot and linux. -- Orjan Friberg FlatFrog Laboratories AB -- To unsubscribe from this list: send the line unsubscribe linux-omap in the body of a message to majord...@vger.kernel.org More majordomo info

Spurious ECC errors with mtd_subpagetest (OMAP3, NAND)

2012-03-02 Thread Orjan Friberg
correction but I'm running with only 1-bit (software) ECC. This is on an old kernel, 2.6.32. Thanks, Orjan -- Orjan Friberg FlatFrog Laboratories AB -- To unsubscribe from this list: send the line unsubscribe linux-omap in the body of a message to majord...@vger.kernel.org More majordomo info

Re: Spurious ECC errors with mtd_subpagetest (OMAP3, NAND)

2012-03-02 Thread Orjan Friberg
On 03/02/2012 05:17 PM, Orjan Friberg wrote: Hi, When running the mtd_subpagetest I'm seeing more or less spurious ECC corrections. I.e., one round may show 4 corrections and the next will show 7, only some of which are the same as the previous 4. FWIW * I'm seeing the same behaviour (i.e

Re: CONFIG_PREEMPT and JFFS2 oops

2012-01-26 Thread Orjan Friberg
On 01/25/2012 10:02 PM, Orjan Friberg wrote: That one-liner was boiled down from the following program, which still oopses instantly: The C program seems to work fine with CONFIG_PREEMPT_NONE=y. If that is indeed the problem I guess it's reasonable that it worked better with PREEMPT_VOLUNTARY

Re: CONFIG_PREEMPT and JFFS2 oops

2012-01-26 Thread Orjan Friberg
with avail_in 0, avail_out 428, total_in 788, total_out 360 calling deflate with avail_in 12, avail_out 428 deflate returned with avail_in 0, avail_out 414, total_in 800, total_out 374 zlib compressed 800 bytes into 380 I'll take a look at what jffs2_do_reserve_space is up to. Thanks. -- Orjan Friberg

Re: CONFIG_PREEMPT and JFFS2 oops

2012-01-26 Thread Orjan Friberg
On 01/26/2012 11:15 AM, Orjan Friberg wrote: problem to mysteriously disappear. Doing this analysis should provide a good clue as to where to look next. I personally would be rather suspicious of that ri-data_crc = cpu_to_je32(crc32(0, comprbuf, cdatalen

Re: CONFIG_PREEMPT and JFFS2 oops

2012-01-26 Thread Orjan Friberg
/2012-January/039442.html if you're interested (though that discussion didn't result in a patch). Thanks, Orjan -- Orjan Friberg FlatFrog Laboratories AB -- To unsubscribe from this list: send the line unsubscribe linux-omap in the body of a message to majord...@vger.kernel.org More majordomo info

Re: CONFIG_PREEMPT and JFFS2 oops

2012-01-26 Thread Orjan Friberg
continuous testing, but whether that's normal I don't know. I see at least some of it being reclaimed when unmounting the JFFS2 partitions (grep jffs2 /proc/slabinfo). -- Orjan Friberg FlatFrog Laboratories AB -- To unsubscribe from this list: send the line unsubscribe linux-omap in the body

CONFIG_PREEMPT and JFFS2 oops

2012-01-25 Thread Orjan Friberg
on each of them. Sometimes the oops trace originates from the garbage collector, sometimes the result is a JFFS2 decompress error. -- Orjan Friberg FlatFrog Laboratories AB [ 81.200805] Unable to handle kernel NULL pointer dereference at virtual address [ 81.217529] pgd

Re: CONFIG_PREEMPT and JFFS2 oops

2012-01-25 Thread Orjan Friberg
On 01/25/2012 09:12 PM, Orjan Friberg wrote: I've boiled it down to whether CONFIG_PREEMPT (bug happens) or CONFIG_PREEMPT_VOLUNTARY (bug doesn't happen) is selected. No, I haven't. The problem disappeared only for while :; do dd if=/dev/zero of=file bs=800 count=1; done That one-liner

USB gadget unreliable on software reboot (BeagleBoard xM)

2011-10-04 Thread Orjan Friberg
of the ordinary. I set musb_debug = 5 in musb_core.c, but no errors are reported. I haven't looked at the MUSB controller registers yet; that's next. Any ideas? Thanks, Orjan -- Orjan Friberg FlatFrog Laboratories AB -- To unsubscribe from this list: send the line unsubscribe linux-omap

copy_to_user speed from dma_alloc_coherent vs. kmalloc buffer

2011-04-20 Thread Orjan Friberg
for the duration of the copy_to_user call, then turn it off again (and flush it from the cache)? * Something else entirely? This is on a 3730, on Linux 2.6.32. Thanks, Orjan -- Orjan Friberg FlatFrog Laboratories AB -- To unsubscribe from this list: send the line unsubscribe linux-omap

Re: copy_to_user speed from dma_alloc_coherent vs. kmalloc buffer

2011-04-20 Thread Orjan Friberg
On 2011-04-20 17:12, Orjan Friberg wrote: What are my options (besides using mmap)? It looks like kmalloc + dma_map_single for the DMA destination buffer and then dma_sync_single_for_{cpu,device} around the call to copy_to_user pretty much does the trick. At least the %sys load measured

OMAP 3730 200 MHz SDRAM config

2011-03-07 Thread Orjan Friberg
for measurements. With big (several MB) sequential writes I get ~1170 MB/s. The theoretical max for a 166 MHz is 166*2 * 4 bytes = 1328 MB/s, so we're almost at 90%. We're not the only process accessing memory, and maybe there's some loss due to SDRAM refresh etc. -- Orjan Friberg FlatFrog Laboratories AB

Re: OMAP 3730 200 MHz SDRAM config

2011-03-07 Thread Orjan Friberg
value they are all identical). But are you saying that the values set by the boot loader are preserved by the kernel? (In that case I wonder what the sdram-micron header file is for :) Thanks, Orjan -- Orjan Friberg FlatFrog Laboratories AB -- To unsubscribe from this list: send the line