From: David Brownell <david-b-yBeKhBN/0LDR7s880joybQ@public.gmane.org>
To: Sascha Hauer <s.hauer-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>
Cc: spi-devel-general-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org,
Mikael Starvik <mikael.starvik-VrBV9hrLPhE@public.gmane.org>,
Hans-Peter Nilsson
<hans-peter.nilsson-VrBV9hrLPhE@public.gmane.org>,
Mike Lavender
<mike-UTnDXsALFwNjMdQLN6DIHgC/G2K4zDHf@public.gmane.org>,
Pierre Ossman
<drzeus-mmc-p3sGCRWkH8CeZLLa646FqQ@public.gmane.org>
Subject: Re: [patch 4/4 2.6.23-rc2 + mm2-git-mmc] mmc_spi host driver
Date: Wed, 29 Aug 2007 09:59:32 -0700 [thread overview]
Message-ID: <200708290959.33584.david-b@pacbell.net> (raw)
In-Reply-To: <20070829100708.GB15021-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>
On Wednesday 29 August 2007, Sascha Hauer wrote:
> Hi,
>
> On Wed, Aug 08, 2007 at 09:12:54AM -0700, David Brownell wrote:
> > +
> > + dev_dbg(&spi->dev, " mmc_spi: STOP_TRAN\n");
> > +
> > + /* Tweak the per-block message we set up earlier by morphing
> > + * it to hold single buffer with the token followed by some
> > + * all-ones bytes ... skip N(BR) (0..1), scan the rest for
> > + * "not busy any longer" status, and leave chip selected.
> > + */
> > + INIT_LIST_HEAD(&host->m.transfers);
> > + list_add(&host->early_status.transfer_list,
> > + &host->m.transfers);
> > +
> > + scratch->status[0] = SPI_TOKEN_STOP_TRAN;
> > + memset(scratch->status + 1, 0xff, statlen - 1);
> > + host->early_status.tx_buf = host->early_status.rx_buf;
> > + host->early_status.tx_dma = host->early_status.rx_dma;
> > + host->early_status.len = 1 + statlen;
> > +
>
> The length to transfer here is statlen, not statlen + 1.
Right -- ACK. Although the code could be shrunk a smidgeon
(and IMO made clearer) by doing the memset of the full buffer,
then just overwriting the first byte with that token.
> With the following
> patch applied the driver works more reliably for me, though not perfect.
> I still get occasional errors like this from some SD cards:
>
> mmcblk0: error 2 sending stop command
That would be an error on the READ path, yes? Because the
SPI protocols only use a STOP command on multiblock reads.
> This is a crc error.
You're sure? On my systems, error 2 == ENOENT, which is
only reported when an MMC or SD card fails CID fetch...
> There may be still problems in my (Hilscher netx)spi driver.
> The mmc over spi stuff is the first testbed for this fresh driver.
Feeling brave, aren't you? :)
> For a
> real crc error I would expect that they are somewhat dependent on the
> clock rate, but this does not seem to be the case. Before going deeper
> here, has any of you seen this or got an idea where to look for it?
Haven't noticed such a beast myself. You can disable CRCs,
that could help rule out CRCs as the cause (or finger them
a bit more clearly).
- Dave
>
> Sascha
>
>
> Signed-off-by: Sascha Hauer <s.hauer-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>
>
> ---
> drivers/mmc/host/mmc_spi.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> Index: linux-2.6-arm/drivers/mmc/host/mmc_spi.c
> ===================================================================
> --- linux-2.6-arm.orig/drivers/mmc/host/mmc_spi.c
> +++ linux-2.6-arm/drivers/mmc/host/mmc_spi.c
> @@ -886,7 +886,7 @@ mmc_spi_data_do(struct mmc_spi_host *hos
> memset(scratch->status + 1, 0xff, statlen - 1);
> host->early_status.tx_buf = host->early_status.rx_buf;
> host->early_status.tx_dma = host->early_status.rx_dma;
> - host->early_status.len = 1 + statlen;
> + host->early_status.len = statlen;
>
> if (host->dma_dev)
> dma_sync_single_for_device(host->dma_dev,
>
>
>
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next prev parent reply other threads:[~2007-08-29 16:59 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-08-08 16:06 [patch 0/4 2.6.23-rc2 + mm2-git-mmc] latest MMC-over-SPI support David Brownell
[not found] ` <200708080906.18993.david-b-yBeKhBN/0LDR7s880joybQ@public.gmane.org>
2007-08-08 16:09 ` [patch 1/4 2.6.23-rc2 + mm2-git-mmc] MMC headers learn about SPI David Brownell
2007-08-08 16:10 ` [patch 2/4 2.6.23-rc2 + mm2-git-mmc] MMC/SD card driver learns SPI David Brownell
2007-08-08 16:11 ` [patch 3/4 2.6.23-rc2 + mm2-git-mmc] MMC core learns about SPI David Brownell
[not found] ` <200708080911.33099.david-b-yBeKhBN/0LDR7s880joybQ@public.gmane.org>
2007-08-09 13:07 ` Pierre Ossman
[not found] ` <20070809150747.62b1447a-mgABNEgzgxm+PRNnhPf8W5YgPPQkE1Si@public.gmane.org>
2007-08-09 15:35 ` David Brownell
[not found] ` <200708090835.42279.david-b-yBeKhBN/0LDR7s880joybQ@public.gmane.org>
2007-08-09 20:18 ` Pierre Ossman
2007-08-12 15:50 ` David Brownell
[not found] ` <200708120850.04271.david-b-yBeKhBN/0LDR7s880joybQ@public.gmane.org>
2007-08-12 15:52 ` Pierre Ossman
2007-08-29 9:22 ` Sascha Hauer
[not found] ` <20070829092247.GA15021-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>
2007-08-29 14:52 ` Pierre Ossman
[not found] ` <20070829165243.0236cc89-mgABNEgzgxm+PRNnhPf8W5YgPPQkE1Si@public.gmane.org>
2007-08-29 16:43 ` David Brownell
[not found] ` <200708290943.59450.david-b-yBeKhBN/0LDR7s880joybQ@public.gmane.org>
2007-10-08 17:09 ` Jan Nikitenko
[not found] ` <470A644A.8030405-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2007-10-10 18:36 ` Pierre Ossman
[not found] ` <c4bc83220710190240wd13bfd1r991ba9b1b1128f6c@mail.gmail.com>
[not found] ` <c4bc83220710190240wd13bfd1r991ba9b1b1128f6c-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2007-10-19 9:50 ` Jan Nikitenko
[not found] ` <c4bc83220710190250m6c3401end194917e2daa9104-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2007-10-22 18:34 ` Pierre Ossman
[not found] ` <20071022203428.300117e4-mgABNEgzgxm+PRNnhPf8W5YgPPQkE1Si@public.gmane.org>
2007-10-23 8:06 ` Jan Nikitenko
[not found] ` <471DAB71.8000808-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2007-10-27 12:08 ` Pierre Ossman
[not found] ` <20071027140823.5d7ec7e2-mgABNEgzgxm+PRNnhPf8W5YgPPQkE1Si@public.gmane.org>
2007-10-27 16:33 ` David Brownell
[not found] ` <200710270933.30538.david-b-yBeKhBN/0LDR7s880joybQ@public.gmane.org>
2007-10-29 8:02 ` Jan Nikitenko
2007-08-08 16:12 ` [patch 4/4 2.6.23-rc2 + mm2-git-mmc] mmc_spi host driver David Brownell
[not found] ` <200708080912.54918.david-b-yBeKhBN/0LDR7s880joybQ@public.gmane.org>
2007-08-29 10:07 ` Sascha Hauer
[not found] ` <20070829100708.GB15021-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>
2007-08-29 16:59 ` David Brownell [this message]
[not found] ` <200708290959.33584.david-b-yBeKhBN/0LDR7s880joybQ@public.gmane.org>
2007-08-29 19:39 ` Pierre Ossman
[not found] ` <20070829213905.71236d24-mgABNEgzgxm+PRNnhPf8W5YgPPQkE1Si@public.gmane.org>
2007-08-29 20:00 ` David Brownell
2007-08-30 8:59 ` Sascha Hauer
[not found] ` <20070830085900.GA18374-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>
2007-08-30 18:56 ` David Brownell
[not found] ` <20070830185623.9C6CD231986-ZcXrCSuhvln6VZ3dlLfH/g4gEjPzgfUyLrfjE7I9kuVHxeISYlDBzl6hYfS7NtTn@public.gmane.org>
2007-08-31 17:00 ` Sascha Hauer
[not found] ` <20070831170054.GA11112-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>
2007-08-31 23:00 ` David Brownell
[not found] ` <20070831230050.4F31F2371AF-ZcXrCSuhvln6VZ3dlLfH/g4gEjPzgfUyLrfjE7I9kuVHxeISYlDBzl6hYfS7NtTn@public.gmane.org>
2007-09-04 10:54 ` Sascha Hauer
[not found] ` <20070904105453.GD7579-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>
2007-11-15 23:30 ` David Brownell
[not found] ` <200711151530.06591.david-b-yBeKhBN/0LDR7s880joybQ@public.gmane.org>
2007-11-16 1:02 ` Hans-Peter Nilsson
[not found] ` <200711160102.lAG12Fdo031436-PT6ZA4s7Vg53Mq0XhIy4CVaTQe2KTcn/@public.gmane.org>
2007-11-16 20:28 ` David Brownell
2007-08-09 10:45 ` [patch 0/4 2.6.23-rc2 + mm2-git-mmc] latest MMC-over-SPI support Anton Vorontsov
2007-08-09 13:05 ` Pierre Ossman
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