From: Boris Brezillon <boris.brezillon@collabora.com>
To: masonccyang@mxic.com.tw
Cc: "Marek Vasut" <marek.vasut@gmail.com>,
bbrezillon@kernel.org, broonie@kernel.org,
devicetree@vger.kernel.org,
"Geert Uytterhoeven" <geert+renesas@glider.be>,
"Simon Horman" <horms@verge.net.au>,
juliensu@mxic.com.tw, lee.jones@linaro.org,
linux-kernel@vger.kernel.org, linux-renesas-soc@vger.kernel.org,
linux-spi@vger.kernel.org, mark.rutland@arm.com,
robh+dt@kernel.org,
"Sergei Shtylyov" <sergei.shtylyov@cogentembedded.com>,
zhengxunli@mxic.com.tw
Subject: Re: [PATCH v9 2/3] spi: Add Renesas R-Car Gen3 RPC-IF SPI controller driver
Date: Wed, 10 Apr 2019 10:11:10 +0200 [thread overview]
Message-ID: <20190410101110.2224eb91@collabora.com> (raw)
In-Reply-To: <OF75EDBF48.5C308F1B-ON482583D8.0027A537-482583D8.002C0A64@mxic.com.tw>
On Wed, 10 Apr 2019 16:01:02 +0800
masonccyang@mxic.com.tw wrote:
> Hi,
>
> > Re: [PATCH v9 2/3] spi: Add Renesas R-Car Gen3 RPC-IF SPI controller
> driver
> >
> > On 4/10/19 3:33 AM, masonccyang@mxic.com.tw wrote:
> > > Hi Sergei,
> > >
> > >> > +static ssize_t rpc_spi_mem_dirmap_write(struct spi_mem_dirmap_desc
> > > *desc,
> > >> > + u64 offs, size_t len, const void *buf)
> > >> > +{
> > >> > + struct rpc_spi *rpc =
> > >> > + spi_controller_get_devdata(desc->mem->spi->controller);
> > >> > + int ret;
> > >> > +
> > >> > + if (offs + desc->info.offset + len > U32_MAX)
> > >> > + return -EINVAL;
> > >> > +
> > >> > + if (len > RPC_WBUF_SIZE)
> > >> > + len = RPC_WBUF_SIZE;
> > >> > +
> > >> > + ret = rpc_spi_set_freq(rpc, desc->mem->spi->max_speed_hz);
> > >> > + if (ret)
> > >> > + return ret;
> > >> > +
> > >> > + rpc_spi_mem_set_prep_op_cfg(desc->mem->spi,
> > >> > + &desc->info.op_tmpl, &offs, &len);
> > >> > +
> > >> > + regmap_update_bits(rpc->regmap, RPC_CMNCR, RPC_CMNCR_MD,
> > > RPC_CMNCR_MD);
> > >> > +
> > >> > + regmap_write(rpc->regmap, RPC_SMDRENR, 0);
> > >> > +
> > >> > + regmap_update_bits(rpc->regmap, RPC_PHYCNT,
> RPC_PHYCNT_STRTIM(7) |
> > >> > + RPC_PHYCNT_WBUF2 | RPC_PHYCNT_WBUF,
> > >> > + RPC_PHYCNT_WBUF2 | RPC_PHYCNT_WBUF);
> > >> > +
> > >> > + memcpy_toio(rpc->wbuf, buf, len);
> > >>
> > >> Wait, doesn't the manual say that the whole 256-byte buffer should
> be
> > >> filled?
>
> it could be less than 256 bytes, i.e., 128 bytes to rpc->wbuf !
>
> I think that short chunks have to be written w/o WBUF (done,
> > > in fact,
> > >> by the HF driver).
> > >>
> > >
> > > From spi-nor.c layer always transfer 256 bytes data with page program
> > > command.
> >
> > Does that apply even for flashes with not-256-byte pages ?
> >
>
> I think it needs to patch in case of nor->page_size = 512 bytes.
I think the main problem here is that you assume the memory is a
NOR :-). Just do what the spi-mem user asks: if he asks you to write
X bytes, then write no more than X bytes. Use whatever trick you have
to make sure this is always true, and if this requires using a slow
path for non-aligned accesses, then do it, because it's better to have
a slow+working memory than a fast+non-working one :P.
next prev parent reply other threads:[~2019-04-10 8:11 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-03-29 8:20 [PATCH v9 0/3] mfd: Add Renesas R-Car Gen3 RPC-IF MFD driver Mason Yang
2019-03-29 8:20 ` [PATCH v9 1/3] mfd: Add Renesas R-Car Gen3 RPC-IF MFD controller driver Mason Yang
2019-03-29 10:43 ` Marek Vasut
2019-03-29 15:12 ` Sergei Shtylyov
2019-03-29 8:20 ` [PATCH v9 2/3] spi: Add Renesas R-Car Gen3 RPC-IF SPI " Mason Yang
2019-03-29 10:44 ` Marek Vasut
2019-03-29 15:52 ` Sergei Shtylyov
[not found] ` <OF7F1B534F.B934A9FE-ON482583D0.001DC618-482583D0.001FE84B@mxic.com.tw>
2019-04-02 20:10 ` Sergei Shtylyov
[not found] ` <OFAEA16021.C7F7B095-ON482583D1.0031A13D-482583D1.00335085@mxic.com.tw>
2019-04-04 18:56 ` Sergei Shtylyov
2019-04-04 19:12 ` Boris Brezillon
2019-04-06 19:59 ` Sergei Shtylyov
2019-04-09 11:20 ` Sergei Shtylyov
2019-04-10 19:47 ` Sergei Shtylyov
2019-04-09 20:07 ` Sergei Shtylyov
[not found] ` <OFC7F0028A.CFF6BD04-ON482583D8.00084FA1-482583D8.0008985F@mxic.com.tw>
2019-04-10 6:27 ` Marek Vasut
[not found] ` <OF75EDBF48.5C308F1B-ON482583D8.0027A537-482583D8.002C0A64@mxic.com.tw>
2019-04-10 8:03 ` Marek Vasut
2019-04-10 8:11 ` Boris Brezillon [this message]
2019-04-10 17:53 ` Sergei Shtylyov
2019-04-13 16:38 ` Sergei Shtylyov
2019-04-13 16:39 ` Sergei Shtylyov
[not found] ` <OF82CE76E9.E6395EF7-ON482583DD.000E37D7-482583DD.000E5077@mxic.com.tw>
2019-04-17 18:44 ` Sergei Shtylyov
[not found] ` <OF4ABCC306.B053BA23-ON482583E0.000F480C-482583E0.000FAD4A@mxic.com.tw>
2019-04-18 19:43 ` Sergei Shtylyov
[not found] ` <OF58AAFF49.C4593DEB-ON482583E1.001D551E-482583E1.001F089D@LocalDomain>
[not found] ` <OFE74649D4.F69BB5EF-ON482583E1.0033F73F-482583E1.00344ED2@mxic.com.tw>
2019-04-22 16:44 ` Sergei Shtylyov
[not found] ` <OF58AAFF49.C4593DEB-ON482583E1.001D551E-482583E1.001F089D@mxic.com.tw>
2019-04-23 7:29 ` Geert Uytterhoeven
2019-05-14 19:06 ` Sergei Shtylyov
2019-05-14 19:13 ` Sergei Shtylyov
2019-03-29 8:20 ` [PATCH v9 3/3] dt-bindings: mfd: Document Renesas R-Car Gen3 RPC-IF controller bindings Mason Yang
2019-03-29 10:45 ` Marek Vasut
2019-03-29 10:49 ` Sergei Shtylyov
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