Re: [PATCH v4 2/2] spi: spi-pic32: Add PIC32 SPI master driver

From	Purna Chandra Mandal <purna.mandal@microchip.com>
Newsgroups	linux.kernel
Subject	Re: [PATCH v4 2/2] spi: spi-pic32: Add PIC32 SPI master driver
Date	2016-03-31 13:20 +0200
Message-ID	<riINQ-451-15@gated-at.bofh.it> (permalink)
References	(2 earlier) <rhWzv-2QS-3@gated-at.bofh.it> <ri0D8-61I-15@gated-at.bofh.it> <ri4GK-pQ-21@gated-at.bofh.it> <rim0W-44B-23@gated-at.bofh.it> <riqxz-7wX-17@gated-at.bofh.it>
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On 03/30/2016 09:18 PM, Mark Brown wrote:

> On Wed, Mar 30, 2016 at 04:19:16PM +0530, Purna Chandra Mandal wrote:
>> On 03/29/2016 09:55 PM, Mark Brown wrote:
>>> On Tue, Mar 29, 2016 at 05:32:41PM +0530, Purna Chandra Mandal wrote:
>>>> MMC_SPI will have to terminate on-going MMC transactions and it is
>>>> done by calling setup(). It is assumed that setup() will always leave
>>>> the chip-select deactivated.
>>> No, this is just completely broken - that's quite simply not what
>>> setup() does.  See spi-summary.  There is *no* code in the core that
>>> terminates ongoing transfers as a result of calling setup(), if that's
>>> happening it's a result of triggering error handling.
>> Description of spi_setup() in spi.c clearly mentions that "When this
>> function returns, the spi device is deselected" and this is only
>> possible if (at least) chip-select is deactivated.
> This doesn't say anything about any ongoing operations!  Trying to do a
> setup() with active transfers on the device is just not sensible, it is
> intended to be used on an idle device.  I would not expect it to work
> reliably on an active device.

agreed.

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[PATCH v4 1/2] dt/bindings: Add bindings for PIC32 SPI peripheral Purna Chandra Mandal <purna.mandal@microchip.com> - 2016-03-23 14:50 +0100
  [PATCH v4 2/2] spi: spi-pic32: Add PIC32 SPI master driver Purna Chandra Mandal <purna.mandal@microchip.com> - 2016-03-23 14:50 +0100
    Re: [PATCH v4 2/2] spi: spi-pic32: Add PIC32 SPI master driver Mark Brown <broonie@kernel.org> - 2016-03-29 09:50 +0200
      Re: [PATCH v4 2/2] spi: spi-pic32: Add PIC32 SPI master driver Purna Chandra Mandal <purna.mandal@microchip.com> - 2016-03-29 14:10 +0200
        Re: [PATCH v4 2/2] spi: spi-pic32: Add PIC32 SPI master driver Mark Brown <broonie@kernel.org> - 2016-03-29 18:30 +0200
          Re: [PATCH v4 2/2] spi: spi-pic32: Add PIC32 SPI master driver Purna Chandra Mandal <purna.mandal@microchip.com> - 2016-03-30 13:00 +0200
            Re: [PATCH v4 2/2] spi: spi-pic32: Add PIC32 SPI master driver Mark Brown <broonie@kernel.org> - 2016-03-30 17:50 +0200
              Re: [PATCH v4 2/2] spi: spi-pic32: Add PIC32 SPI master driver Purna Chandra Mandal <purna.mandal@microchip.com> - 2016-03-31 13:20 +0200

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