On Mon, 1 Oct 2018 22:01:27 +0000 Chris Packham <Chris.Packham@xxxxxxxxxxxxxxxxxxx> wrote: > On 02/10/18 10:41, Boris Brezillon wrote: > > On Mon, 1 Oct 2018 22:34:38 +0200 > > Boris Brezillon <boris.brezillon@xxxxxxxxxxx> wrote: > > > >>> > >>> I'd previously tried readl() based on the same hunch. No change. > >>> > >>> I think my snippet above might be misleading. While a delay between > >>> readl_relaxed() and the if should not change the outcome, this is also a > >>> delay between marvell_nfc_enable_int() and marvell_nfc_disable_int() > >>> which is probably more significant. Sure enough if I move the delay to > >>> just before the marvell_nfc_disable_int() the error is not seen. > >> > >> AFAICT, your timeout always happens when waiting for RDREQ, not RDYM. > >> So maybe disabling MRDY too early has a side-effect on the RDREQ event. > > > > Can you try with this patch [1]? It should ensure that NDSR_RDY bits > > are cleared before starting an operation. > > > > [1]http://code.bulix.org/lgs30c-468205 > > > > No luck. I applied that on top of Daniel's and got the same result. > > One thing that does look promising is the following modification of > Daniel's patch[1]. Which moves the RDY check to before where the > interrupts are enabled. Except we still don't know why this is happening, and I'm not sure I want to take a fix without understanding why it does fix the problem. Also, it looks like complete() is not called until the RDDREQ, WRDREQ and WRCMDREQ are cleared in the interrupt handler [1], which is weird. Miquel, do you happen to remember why you had to do that? [1]https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/mtd/nand/raw/marvell_nand.c?h=v4.19-rc6#n689
