Re: [PATCH v4 1/2] mtd: rawnand: Add Macronix Raw NAND controller

masonccyang
2019-06-28T08:32:39Z

Hi Miquel,

> >
> > > > Add a driver for Macronix raw NAND controller.
> > >
> > > Could you pass userspace major MTD tests and can you
attach/mount/edit
> > > a UBI/UBIFS storage?
> >
> > mtd_debug passed and using dd utility to read and write
> > with md5sum checking passed.
>
> Please don't use dd, use nanddump/nandwrite/flasherase/nandbiterrs and
> run the other tests from the mtd-utils test suite (available in
> Buildroot for instance).
>

Got it.

But may I know why 'dd' utility is not preferences ?
I generate a random data file and write to Flash by
using dd with bs=page size and read data back from Flash.
Checking data by md5sum.
The write and read testing data size is easily adjustable.

> >
> > > > +static int mxic_nfc_clk_enable(struct mxic_nand_ctlr *nfc)
> > > > +{
> > > > + int ret;
> > > > +
> > > > + ret = clk_prepare_enable(nfc->send_clk);
> > > > + if (ret)
> > > > + return ret;
> > > > +
> > > > + ret = clk_prepare_enable(nfc->send_dly_clk);
> > > > + if (ret)
> > > > + goto err_send_dly_clk;
> > >
> > > I'm not sure why you only enable 2 out of 3 clocks and also why ou
> > > handle two of them here (which is great, I prefer having a separate
> > > helper for that) and the other one elsewhere?
> > >
> >
> > send_clk and send_dly_clk are device domain clocks.
> >
> > send_clk is clock without phase delay to ps_clk, used for sending
device
> > signals except for SIO[7:0].
> > send_dly_clk is clock with phase delay to ps_clk, used for sending
> > SIO[7:0]
> >
> > ps_clk is system domain clock and it's a source clock of send_clk and
> > send_dly_clk.
>
> And why is that explaining the fact that you configure them in
> different places? You can explain this with a nice comment at the top
> of the function, but I would rather prefer that you handle all three
> clocks in one go if possible.
>

okay, will patch it.

> > > > +static int mxic_nfc_data_xfer(struct mxic_nand_ctlr *nfc, const
void
> > *txbuf,
> > > > + void *rxbuf, unsigned int len)
> > > > +{
> > > > + unsigned int pos = 0;
> > > > +
> > > > + while (pos < len) {
> > > > + unsigned int nbytes = len - pos;
> > > > + u32 data = 0xffffffff;
> > > > + u32 sts;
> > > > + int ret;
> > > > +
> > > > + if (nbytes > 4)
> > > > + nbytes = 4;
> > > > +
> > > > + if (txbuf)
> > > > + memcpy(&data, txbuf + pos, nbytes);
> > > > +
> > > > + ret = readl_poll_timeout(nfc->regs + INT_STS, sts,
> > > > + sts & INT_TX_EMPTY, 0, USEC_PER_SEC);
> > > > + if (ret)
> > > > + return ret;
> > > > +
> > > > + writel(data, nfc->regs + TXD(nbytes % 4));
> > > > +
> > > > + if (rxbuf) {
> > > > + ret = readl_poll_timeout(nfc->regs + INT_STS, sts,
> > > > + sts & INT_TX_EMPTY, 0,
> > > > + USEC_PER_SEC);
> > > > + if (ret)
> > > > + return ret;
> > > > +
> > > > + ret = readl_poll_timeout(nfc->regs + INT_STS, sts,
> > > > + sts & INT_RX_NOT_EMPTY, 0,
> > > > + USEC_PER_SEC);
> > > > + if (ret)
> > > > + return ret;
> > > > +
> > > > + data = readl(nfc->regs + RXD);
> > > > + data >>= (8 * (4 - nbytes));
> > > > + memcpy(rxbuf + pos, &data, nbytes);
> > > > + WARN_ON(readl(nfc->regs + INT_STS) & INT_RX_NOT_EMPTY);
> > > > + } else {
> > > > + readl(nfc->regs + RXD);
> > > > + }
> > > > + WARN_ON(readl(nfc->regs + INT_STS) & INT_RX_NOT_EMPTY);
> > >
> > > WARN_ON() is maybe a bit overkill here?
> >
> > should I remove it ?
>
> I would stick to regular dev_warn.

Got it, will patch it.

thanks & best regards,
Mason

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CONFIDENTIALITY NOTE:

This e-mail and any attachments may contain confidential information and/or personal data, which is protected by applicable laws. Please be reminded that duplication, disclosure, distribution, or use of this e-mail (and/or its attachments) or any part thereof is prohibited. If you receive this e-mail in error, please notify us immediately and delete this mail as well as its attachment(s) from your system. In addition, please be informed that collection, processing, and/or use of personal data is prohibited unless expressly permitted by personal data protection laws. Thank you for your attention and cooperation.

Macronix International Co., Ltd.

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