2015-09-19 19:56 GMT+02:00 Mark Brown <[email protected]>: > On Fri, Sep 18, 2015 at 02:38:27PM +0200, Jean-Michel Hautbois wrote: >> Hi, >> >> I am wondering why in spi-imx the spi_imx_pio_transfer() function is >> calling wait_for_completion() and not wait_for_completion_timeout() as >> in the spi_imx_dma_transfer() one. >> I can't see a good reason for this, maybe should it be calculated >> based on the spi clock and transfer->len, or at least be the same as >> IMX_DMA_TIMEOUT which is 3 seconds ? >> If you want it, I have a patch, just tell me if you are interested and >> if you prefer a calculated timeout or even something else ? > > A calculated timeout is probably best.
Well, it depends... If you have a 20MHz clock, then you can transfer a byte in 4µs. As most of the time pio_transfer is used for 8 to 32 bytes max, it would be irrelevant to use such a small timeout. I can obviously do it, but not sure if using a small (say, 100ms) timeout would not be better. JM -- To unsubscribe from this list: send the line "unsubscribe linux-spi" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
