From mboxrd@z Thu Jan 1 00:00:00 1970 From: w.sang@pengutronix.de (Wolfram Sang) Date: Tue, 19 Jul 2011 15:36:02 +0200 Subject: [i.MX28 GPMI] problem overwriting all-0xff data in NAND In-Reply-To: <20005.21635.427202.49313@ipc1.ka-ro> References: <20004.12663.29494.339601@ipc1.ka-ro> <20110718164354.GA3328@S2100-06.ap.freescale.net> <4E24E804.10002@freescale.com> <20005.7677.145955.789329@ipc1.ka-ro> <4E252C51.8070900@freescale.com> <20005.21635.427202.49313@ipc1.ka-ro> Message-ID: <20110719133602.GJ1951@pengutronix.de> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org > > >> I am debugging the DMA bug now. and I will send it out when i fix it. > > >> > > > What sort of DMA bug? > > > > > > > The DMA may time-out. :( > > > > The DMA time-out may occur in two situations: > > [1] send a command DMA descriptor, see the nfc->send_command() function. > > [2] read the non-ecc data from nand, see the nfc->read_data() function. > > > > I don't know why. Maybe caused by the timing, or something else. I am confused. The send-command DMA timeout prevents any write for me. You guys surely would have noticed if you have been bitten as well. Does it depend on the NAND chip? > Maybe you are missing this patch: > http://lists.infradead.org/pipermail/linux-arm-kernel/2011-April/049105.html > I sent it in April, but apparently it has not been integrated in > mainline or the pengutronix git. Well, just resend them; might be worth trying Shawn's comment, too (if that reset is really needed). BTW they didn't help for my case :( Regards, Wolfram -- Pengutronix e.K. | Wolfram Sang | Industrial Linux Solutions | http://www.pengutronix.de/ | -------------- next part -------------- A non-text attachment was scrubbed... Name: not available Type: application/pgp-signature Size: 198 bytes Desc: Digital signature URL: