Thank you for your reply. I am wondering if there is going to be any improvements if I change the priority of the garbage collector thread. I will try and let you know. Best regards Andreas 2011/11/28 Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxxxx>: > Hello Andreas, > > On Mon, Nov 28, 2011 at 02:45:26AM +0000, Andreas O wrote: >> I am using a real-time 2.6.33.7 version on ARM and I have noticed some >> problems with the NAND. After a power cycle I see messages like >> "mtd->read( ) returned ECC Error." It is quite strange. >> Example: >> >> mtd->read(0x1fba0 bytes from 0x4e0460) returned ECC error >> mtd->read(0x1d520 bytes from 0x4e2ae0) returned ECC error >> >> Initially, I make write to the NAND the jff2 filesystem and when I >> boot for first time >> there are no ECC errors at all. After the first power cycler, some ECC >> errors will appear. >> If I do a second power cycle, more may be would appear. >> If I repeat again the same procedure, writing again the rootfile >> system to the NAND, after a power cycle the ECC errors will come from >> the same region (0x4exxxx). I have used different types of NAND, and >> the problem is the same. >> >> I think it might have to do with a combination of the RT and jffs2, >> Jffs2 garbage collector thread. The GC thread might need priority >> change as it takes the lock for performing the scan and may sleep for >> longer within the RT world. Therefore writes do not happen that often, >> therefore those ECC errors from un-flushed wbuf buffers. >> >> Have you seen similar behaviour before with RT and Jffs2? > How do you restart. Just pressing reset or unplugging is expected to > yield warnings by jffs2. See > > http://www.linux-mtd.infradead.org/faq/jffs2.html#L_messages. > > Maybe rt makes it more likely for these to appear, but the problem is > not specific to rt. > > Best regards > Uwe > > -- > Pengutronix e.K. | Uwe Kleine-König | > Industrial Linux Solutions | http://www.pengutronix.de/ | > -- To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
