| drivers: spi: backport PM improvement for SPI framework |
| |
| Fix PM improvement for SPI framework. |
| As to set_cs takes effect immediately, power spi |
| is needed when setup spi. |
| |
| (cherry picked from commit d948e6ca189985495a21cd622c31e30e72b6b688) |
| Link: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/drivers/spi/spi.c?h=v5.16-rc4&id=d948e6ca189985495a21cd622c31e30e72b6b688 |
| (cherry picked from commit 57a9460705f105e1d79d1410c5cfe285beda8986) |
| Link: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/drivers/spi/spi.c?h=v5.16-rc4&id=57a9460705f105e1d79d1410c5cfe285beda8986 |
| |
| --- a/drivers/spi/spi.c |
| +++ b/drivers/spi/spi.c |
| @@ -3170,7 +3170,29 @@ int spi_setup(struct spi_device *spi) |
| if (spi->controller->setup) |
| status = spi->controller->setup(spi); |
| |
| - spi_set_cs(spi, false); |
| + if (spi->controller->auto_runtime_pm && spi->controller->set_cs) { |
| + status = pm_runtime_get_sync(spi->controller->dev.parent); |
| + if (status < 0) { |
| + pm_runtime_put_noidle(spi->controller->dev.parent); |
| + dev_err(&spi->controller->dev, "Failed to power device: %d\n", |
| + status); |
| + return status; |
| + } |
| + |
| + /* |
| + * We do not want to return positive value from pm_runtime_get, |
| + * there are many instances of devices calling spi_setup() and |
| + * checking for a non-zero return value instead of a negative |
| + * return value. |
| + */ |
| + status = 0; |
| + |
| + spi_set_cs(spi, false); |
| + pm_runtime_mark_last_busy(spi->controller->dev.parent); |
| + pm_runtime_put_autosuspend(spi->controller->dev.parent); |
| + } else { |
| + spi_set_cs(spi, false); |
| + } |
| |
| if (spi->rt && !spi->controller->rt) { |
| spi->controller->rt = true; |
| -- |
| 2.18.0 |
| |