Messages in this thread Patch in this message | | | Subject | Re: [BUG] SPI broken for SPI based panel drivers | From | "H. Nikolaus Schaller" <> | Date | Tue, 1 Dec 2020 09:59:43 +0100 |
| |
Hi Sven,
> Am 30.11.2020 um 21:13 schrieb Sven Van Asbroeck <thesven73@gmail.com>: > > Hi Nikolaus, thank you for reaching out ! > > On Mon, Nov 30, 2020 at 2:06 PM H. Nikolaus Schaller <hns@goldelico.com> wrote: >> >> But reverting your patch brings back the display. So it appears as if it does not >> fix a breakage, rather breaks a previously working setup. > > The patch in question fixes an important breakage: before the patch, literally > hundreds of SPI drivers no longer worked - only if the SPI bus master > driver was using gpio descriptors. > > We knew that there was a chance that our fix would break something else. > But hopefully "it fixes more than it breaks"
Then it should not have been applied to mainline but fully worked out and tested.
> >> >> What should we do? >> > > Can you try the following patch ?
Unfortunately it doesn't seem to fix it. And combined with the second proposed fix also not.
BR and thanks, Nikolaus
my combined change:
diff --git a/drivers/spi/spi-gpio.c b/drivers/spi/spi-gpio.c index 7ceb0ba27b755c..ec2da62716a279 100644 --- a/drivers/spi/spi-gpio.c +++ b/drivers/spi/spi-gpio.c @@ -208,8 +208,8 @@ static void spi_gpio_chipselect(struct spi_device *spi, int is_active) if (spi_gpio->cs_gpios) { struct gpio_desc *cs = spi_gpio->cs_gpios[spi->chip_select]; - /* SPI chip selects are normally active-low */ - gpiod_set_value_cansleep(cs, (spi->mode & SPI_CS_HIGH) ? is_active : !is_active); + /* SPI chip select polarity handled by gpiolib*/ + gpiod_set_value_cansleep(cs, is_active); } } @@ -226,8 +226,7 @@ static int spi_gpio_setup(struct spi_device *spi) if (spi_gpio->cs_gpios) { cs = spi_gpio->cs_gpios[spi->chip_select]; if (!spi->controller_state && cs) - status = gpiod_direction_output(cs, - !(spi->mode & SPI_CS_HIGH)); + status = gpiod_direction_output(cs, false); } if (!status)
| |