From 5457773ef99f25fcc4b238ac76b68e28273250f4 Mon Sep 17 00:00:00 2001 From: Tobias Schramm Date: Fri, 27 Aug 2021 07:03:57 +0200 Subject: [PATCH 1/2] spi: rockchip: handle zero length transfers without timing out Previously zero length transfers submitted to the Rokchip SPI driver would time out in the SPI layer. This happens because the SPI peripheral does not trigger a transfer completion interrupt for zero length transfers. Fix that by completing zero length transfers immediately at start of transfer. Signed-off-by: Tobias Schramm Link: https://lore.kernel.org/r/20210827050357.165409-1-t.schramm@manjaro.org Signed-off-by: Mark Brown --- drivers/spi/spi-rockchip.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/spi/spi-rockchip.c b/drivers/spi/spi-rockchip.c index 540861ca2ba3..553b6b9d0222 100644 --- a/drivers/spi/spi-rockchip.c +++ b/drivers/spi/spi-rockchip.c @@ -600,6 +600,12 @@ static int rockchip_spi_transfer_one( int ret; bool use_dma; + /* Zero length transfers won't trigger an interrupt on completion */ + if (!xfer->len) { + spi_finalize_current_transfer(ctlr); + return 1; + } + WARN_ON(readl_relaxed(rs->regs + ROCKCHIP_SPI_SSIENR) && (readl_relaxed(rs->regs + ROCKCHIP_SPI_SR) & SR_BUSY)); From 2bab94090b01bc593d8bc25f68df41f198721173 Mon Sep 17 00:00:00 2001 From: Guenter Roeck Date: Mon, 6 Sep 2021 21:53:58 -0700 Subject: [PATCH 2/2] spi: tegra20-slink: Declare runtime suspend and resume functions conditionally The following build error is seen with CONFIG_PM=n. drivers/spi/spi-tegra20-slink.c:1188:12: error: 'tegra_slink_runtime_suspend' defined but not used drivers/spi/spi-tegra20-slink.c:1200:12: error: 'tegra_slink_runtime_resume' defined but not used Declare the functions only if PM is enabled. While at it, remove the unnecessary forward declarations. Signed-off-by: Guenter Roeck Reviewed-by: Geert Uytterhoeven Acked-by: Thierry Reding Link: https://lore.kernel.org/r/20210907045358.2138282-1-linux@roeck-us.net Signed-off-by: Mark Brown --- drivers/spi/spi-tegra20-slink.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/drivers/spi/spi-tegra20-slink.c b/drivers/spi/spi-tegra20-slink.c index ebd27f883033..8ce840c7ecc8 100644 --- a/drivers/spi/spi-tegra20-slink.c +++ b/drivers/spi/spi-tegra20-slink.c @@ -204,9 +204,6 @@ struct tegra_slink_data { struct dma_async_tx_descriptor *tx_dma_desc; }; -static int tegra_slink_runtime_suspend(struct device *dev); -static int tegra_slink_runtime_resume(struct device *dev); - static inline u32 tegra_slink_readl(struct tegra_slink_data *tspi, unsigned long reg) { @@ -1185,6 +1182,7 @@ static int tegra_slink_resume(struct device *dev) } #endif +#ifdef CONFIG_PM static int tegra_slink_runtime_suspend(struct device *dev) { struct spi_master *master = dev_get_drvdata(dev); @@ -1210,6 +1208,7 @@ static int tegra_slink_runtime_resume(struct device *dev) } return 0; } +#endif /* CONFIG_PM */ static const struct dev_pm_ops slink_pm_ops = { SET_RUNTIME_PM_OPS(tegra_slink_runtime_suspend,