| From 95a98fe45ef7a1c267c83af3ee0dde4ba7f5e9da Mon Sep 17 00:00:00 2001 |
| From: Tudor Ambarus <tudor.ambarus@microchip.com> |
| Date: Wed, 19 Jun 2019 14:38:28 +0000 |
| Subject: spi: fix ctrl->num_chipselect constraint |
| |
| [ Upstream commit f9481b08220d7dc1ff21e296a330ee8b721b44e4 ] |
| |
| at91sam9g25ek showed the following error at probe: |
| atmel_spi f0000000.spi: Using dma0chan2 (tx) and dma0chan3 (rx) |
| for DMA transfers |
| atmel_spi: probe of f0000000.spi failed with error -22 |
| |
| Commit 0a919ae49223 ("spi: Don't call spi_get_gpio_descs() before device name is set") |
| moved the calling of spi_get_gpio_descs() after ctrl->dev is set, |
| but didn't move the !ctrl->num_chipselect check. When there are |
| chip selects in the device tree, the spi-atmel driver lets the |
| SPI core discover them when registering the SPI master. |
| The ctrl->num_chipselect is thus expected to be set by |
| spi_get_gpio_descs(). |
| |
| Move the !ctlr->num_chipselect after spi_get_gpio_descs() as it was |
| before the aforementioned commit. While touching this block, get rid |
| of the explicit comparison with 0 and update the commenting style. |
| |
| Fixes: 0a919ae49223 ("spi: Don't call spi_get_gpio_descs() before device name is set") |
| Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com> |
| Signed-off-by: Mark Brown <broonie@kernel.org> |
| Signed-off-by: Sasha Levin <sashal@kernel.org> |
| --- |
| drivers/spi/spi.c | 12 +++++++----- |
| 1 file changed, 7 insertions(+), 5 deletions(-) |
| |
| diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c |
| index 5e4654032bfa..29916e446143 100644 |
| --- a/drivers/spi/spi.c |
| +++ b/drivers/spi/spi.c |
| @@ -2286,11 +2286,6 @@ int spi_register_controller(struct spi_controller *ctlr) |
| if (status) |
| return status; |
| |
| - /* even if it's just one always-selected device, there must |
| - * be at least one chipselect |
| - */ |
| - if (ctlr->num_chipselect == 0) |
| - return -EINVAL; |
| if (ctlr->bus_num >= 0) { |
| /* devices with a fixed bus num must check-in with the num */ |
| mutex_lock(&board_lock); |
| @@ -2361,6 +2356,13 @@ int spi_register_controller(struct spi_controller *ctlr) |
| } |
| } |
| |
| + /* |
| + * Even if it's just one always-selected device, there must |
| + * be at least one chipselect. |
| + */ |
| + if (!ctlr->num_chipselect) |
| + return -EINVAL; |
| + |
| status = device_add(&ctlr->dev); |
| if (status < 0) { |
| /* free bus id */ |
| -- |
| 2.20.1 |
| |
