From: "Franklin S Cooper Jr." <fcooper@ti.com>
To: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
<linux-spi@vger.kernel.org>, Mark Brown <broonie@kernel.org>,
Sekhar Nori <nsekhar@ti.com>, <ssantosh@kernel.org>,
"Ivan T. Ivanov" <iivanov@mm-sol.com>, <m-karicheri2@ti.com>,
"Ivan T. Ivanov" <iivanov.xz@gmail.com>,
Jarkko Nikula <jarkko.nikula@linux.intel.com>,
<hkallweit1@gmail.com>
Subject: Re: [PATCH v2] spi: Setup the master controller driver before setting the chipselect
Date: Fri, 16 Oct 2015 10:47:27 -0500 [thread overview]
Message-ID: <56211C0F.4090102@ti.com> (raw)
In-Reply-To: <CAHp75VdexZWSEEM8xjYEx9WU4dbrNrXeczvBpyKcRKn-qMN=-g@mail.gmail.com>
On 10/16/2015 10:45 AM, Andy Shevchenko wrote:
> On Fri, Oct 16, 2015 at 6:29 PM, Franklin S Cooper Jr <fcooper@ti.com> wrote:
>> SPI controllers may need to be properly setup before chip selects
>> can be used. Therefore, wait until the spi controller has a chance
>> to perform their setup procedure before trying to use the chip
>> select.
>>
>> This also insures that the chip selects pins are in a good
>> state before asseting them which otherwise may cause confusion.
>>
>> Signed-off-by: Franklin S Cooper Jr <fcooper@ti.com>
> Does it mean I have to test it again?
Oops sorry. No the patch hasn't changed. I can shoot a v3 with your tested by included.
>
>> ---
>> Keystone 2 devices currently fail to boot in linux-next after the
>> below commit was applied:
>>
>> spi: bitbang: switch to the generic implementation of transfer_one_message
>> commit: 0037686596832572bbca05ab168d9884d7d704c1
>>
>> This patch allows Keystone 2 devices to boot again in linux-next.
>>
>> Tested this patch on K2E evm and am437 starterkit which both have SPI
>> devices to insure regressions aren't seen.
>>
>> V2 Changes:
>> Update commit message.
>>
>> drivers/spi/spi.c | 4 ++--
>> 1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
>> index 4c638f3..9d5525a 100644
>> --- a/drivers/spi/spi.c
>> +++ b/drivers/spi/spi.c
>> @@ -2059,11 +2059,11 @@ int spi_setup(struct spi_device *spi)
>> if (!spi->max_speed_hz)
>> spi->max_speed_hz = spi->master->max_speed_hz;
>>
>> - spi_set_cs(spi, false);
>> -
>> if (spi->master->setup)
>> status = spi->master->setup(spi);
>>
>> + spi_set_cs(spi, false);
>> +
>> dev_dbg(&spi->dev, "setup mode %d, %s%s%s%s%u bits/w, %u Hz max --> %d\n",
>> (int) (spi->mode & (SPI_CPOL | SPI_CPHA)),
>> (spi->mode & SPI_CS_HIGH) ? "cs_high, " : "",
>> --
>> 2.6.1
>>
>
>
next prev parent reply other threads:[~2015-10-16 15:47 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-10-16 15:29 [PATCH v2] spi: Setup the master controller driver before setting the chipselect Franklin S Cooper Jr
2015-10-16 15:45 ` Andy Shevchenko
2015-10-16 15:47 ` Franklin S Cooper Jr. [this message]
2015-10-16 15:55 ` Andy Shevchenko
2015-10-27 12:22 ` Franklin S Cooper Jr.
2015-10-27 13:11 ` Grygorii Strashko
2015-10-27 13:34 ` Grygorii Strashko
2015-10-28 0:33 ` Mark Brown
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