Re: [PATCH 1/2] spi: spi-omap2-mcspi.c: Add dts for slave device configuration.

2013-06-06 Thread Mark Brown 
On Thu, Jun 06, 2013 at 01:08:46PM +0300, Illia Smyrnov wrote:
 On 06/05/2013 02:57 PM, Mark Brown wrote:

 Turbo mode gives the expected results not for all cases. There are
 some limitations:
 - works only if a single channel is enabled (no effect when several
 channels are enable);
 - improves the throughput on RX direction only;
 - effective only when a transfer exceeds two words. For single SPI
 word transfers OMAP TRM [1] recommends deactivate turbo mode.

 So it is useful to have the property in DT, that allow us to switch
 turbo mode off/on for certain slave.

Why?  These sound like conditions that can readily be detected at
runtime.


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Re: [PATCH 1/2] spi: spi-omap2-mcspi.c: Add dts for slave device configuration.

2013-06-05 Thread Mark Brown 
On Wed, Jun 05, 2013 at 02:39:57PM +0300, Illia Smyrnov wrote:

 +SPI Controller specific data in SPI slave nodes:
 +- The spi slave nodes can provide the following information which is used
 +  by the spi controller:
 +  - ti,spi-turbo-mode: Set turbo mode for this device.
 +

What is turb mode and why would we not want to just enable it all the
time?  Based on this documentation it's not really possible to tell...


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