Re: [PATCH] spi: Avoid setting the chip select if we don't need to

On Mon, 29 Jun 2020 16:41:06 -0700, Douglas Anderson wrote: > On some SPI controllers (like spi-geni-qcom) setting the chip select > is a heavy operation. For instance on spi-geni-qcom, with the current > code, is was measured as taking upwards of 20 us. Even on SPI > controllers that aren't as

Re: [PATCH] spi: Avoid setting the chip select if we don't need to

On Wed, Jul 01, 2020 at 06:26:24AM +, Ardelean, Alexandru wrote: > On Mon, 2020-06-29 at 16:41 -0700, Douglas Anderson wrote: > > + spi->controller->last_cs_enable = enable; > > + spi->controller->last_cs_mode_high = spi->mode & SPI_CS_HIGH; > I don't feel like this is the best approach

Re: [PATCH] spi: Avoid setting the chip select if we don't need to

On Mon, 2020-06-29 at 16:41 -0700, Douglas Anderson wrote: > [External] > > On some SPI controllers (like spi-geni-qcom) setting the chip select > is a heavy operation. For instance on spi-geni-qcom, with the current > code, is was measured as taking upwards of 20 us. Even on SPI > controllers