From: Felix Gu Date: Fri, 22 May 2026 12:40:48 +0000 (+0800) Subject: spi: atmel: fix DMA channel and bounce buffer leaks X-Git-Url: http://git.ipfire.org/gitweb/?a=commitdiff_plain;h=bd7e9843ec95bffe2643c901dd625f0bab32e639;p=thirdparty%2Fkernel%2Flinux.git spi: atmel: fix DMA channel and bounce buffer leaks The original code set use_dma to false when dma_alloc_coherent() for bounce buffers failed, but DMA channels acquired earlier via atmel_spi_configure_dma() were never freed. When devm_request_irq() or clk_prepare_enable() failed later in probe, the driver also did not release DMA channels or bounce buffers already allocated. The out_free_dma error path released DMA channels but did not free the bounce buffers. Fix by moving bounce buffer allocation into atmel_spi_configure_dma() and registering the devres cleanup for DMA channels and bounce buffers. Fixes: a9889ed62d06 ("spi: atmel: Implements transfers with bounce buffer") Signed-off-by: Felix Gu Link: https://patch.msgid.link/20260522-atmel-v3-1-23f8c6e6aa43@gmail.com Signed-off-by: Mark Brown --- diff --git a/drivers/spi/spi-atmel.c b/drivers/spi/spi-atmel.c index 25aa294631c83..c8012c82c3a78 100644 --- a/drivers/spi/spi-atmel.c +++ b/drivers/spi/spi-atmel.c @@ -559,6 +559,38 @@ static int atmel_spi_dma_slave_config(struct atmel_spi *as, u8 bits_per_word) return err; } +static void atmel_spi_release_dma(void *data) +{ + struct spi_controller *host = data; + struct atmel_spi *as = spi_controller_get_devdata(host); + struct device *dev = &as->pdev->dev; + + if (host->dma_tx) { + dma_release_channel(host->dma_tx); + host->dma_tx = NULL; + } + + if (host->dma_rx) { + dma_release_channel(host->dma_rx); + host->dma_rx = NULL; + } + + if (IS_ENABLED(CONFIG_SOC_SAM_V4_V5)) { + if (as->addr_tx_bbuf) { + dma_free_coherent(dev, SPI_MAX_DMA_XFER, + as->addr_tx_bbuf, + as->dma_addr_tx_bbuf); + as->addr_tx_bbuf = NULL; + } + if (as->addr_rx_bbuf) { + dma_free_coherent(dev, SPI_MAX_DMA_XFER, + as->addr_rx_bbuf, + as->dma_addr_rx_bbuf); + as->addr_rx_bbuf = NULL; + } + } +} + static int atmel_spi_configure_dma(struct spi_controller *host, struct atmel_spi *as) { @@ -569,7 +601,8 @@ static int atmel_spi_configure_dma(struct spi_controller *host, if (IS_ERR(host->dma_tx)) { err = PTR_ERR(host->dma_tx); dev_dbg(dev, "No TX DMA channel, DMA is disabled\n"); - goto error_clear; + host->dma_tx = NULL; + return err; } host->dma_rx = dma_request_chan(dev, "rx"); @@ -580,26 +613,45 @@ static int atmel_spi_configure_dma(struct spi_controller *host, * requested tx channel. */ dev_dbg(dev, "No RX DMA channel, DMA is disabled\n"); - goto error; + host->dma_rx = NULL; + goto err_release_dma; } err = atmel_spi_dma_slave_config(as, 8); if (err) - goto error; + goto err_release_dma; + + if (IS_ENABLED(CONFIG_SOC_SAM_V4_V5)) { + as->addr_tx_bbuf = dma_alloc_coherent(dev, SPI_MAX_DMA_XFER, + &as->dma_addr_tx_bbuf, + GFP_KERNEL | GFP_DMA); + if (!as->addr_tx_bbuf) { + err = -ENOMEM; + goto err_release_dma; + } + + as->addr_rx_bbuf = dma_alloc_coherent(dev, SPI_MAX_DMA_XFER, + &as->dma_addr_rx_bbuf, + GFP_KERNEL | GFP_DMA); + if (!as->addr_rx_bbuf) { + err = -ENOMEM; + goto err_release_dma; + } + } + + err = devm_add_action_or_reset(dev, atmel_spi_release_dma, host); + if (err) + return err; dev_info(&as->pdev->dev, - "Using %s (tx) and %s (rx) for DMA transfers\n", - dma_chan_name(host->dma_tx), - dma_chan_name(host->dma_rx)); + "Using %s (tx) and %s (rx) for DMA transfers\n", + dma_chan_name(host->dma_tx), dma_chan_name(host->dma_rx)); return 0; -error: - if (!IS_ERR(host->dma_rx)) - dma_release_channel(host->dma_rx); - if (!IS_ERR(host->dma_tx)) - dma_release_channel(host->dma_tx); -error_clear: - host->dma_tx = host->dma_rx = NULL; + +err_release_dma: + atmel_spi_release_dma(host); + return err; } @@ -611,18 +663,6 @@ static void atmel_spi_stop_dma(struct spi_controller *host) dmaengine_terminate_all(host->dma_tx); } -static void atmel_spi_release_dma(struct spi_controller *host) -{ - if (host->dma_rx) { - dma_release_channel(host->dma_rx); - host->dma_rx = NULL; - } - if (host->dma_tx) { - dma_release_channel(host->dma_tx); - host->dma_tx = NULL; - } -} - /* This function is called by the DMA driver from tasklet context */ static void dma_callback(void *data) { @@ -1581,30 +1621,6 @@ static int atmel_spi_probe(struct platform_device *pdev) as->use_pdc = true; } - if (IS_ENABLED(CONFIG_SOC_SAM_V4_V5)) { - as->addr_rx_bbuf = dma_alloc_coherent(&pdev->dev, - SPI_MAX_DMA_XFER, - &as->dma_addr_rx_bbuf, - GFP_KERNEL | GFP_DMA); - if (!as->addr_rx_bbuf) { - as->use_dma = false; - } else { - as->addr_tx_bbuf = dma_alloc_coherent(&pdev->dev, - SPI_MAX_DMA_XFER, - &as->dma_addr_tx_bbuf, - GFP_KERNEL | GFP_DMA); - if (!as->addr_tx_bbuf) { - as->use_dma = false; - dma_free_coherent(&pdev->dev, SPI_MAX_DMA_XFER, - as->addr_rx_bbuf, - as->dma_addr_rx_bbuf); - } - } - if (!as->use_dma) - dev_info(host->dev.parent, - " can not allocate dma coherent memory\n"); - } - if (as->caps.has_dma_support && !as->use_dma) dev_info(&pdev->dev, "Atmel SPI Controller using PIO only\n"); @@ -1664,13 +1680,10 @@ static int atmel_spi_probe(struct platform_device *pdev) out_free_dma: pm_runtime_disable(&pdev->dev); pm_runtime_set_suspended(&pdev->dev); - - if (as->use_dma) - atmel_spi_release_dma(host); - spi_writel(as, CR, SPI_BIT(SWRST)); spi_writel(as, CR, SPI_BIT(SWRST)); /* AT91SAM9263 Rev B workaround */ - clk_disable_unprepare(as->gclk); + if (as->gclk) + clk_disable_unprepare(as->gclk); out_disable_clk: clk_disable_unprepare(clk); @@ -1687,18 +1700,8 @@ static void atmel_spi_remove(struct platform_device *pdev) spi_unregister_controller(host); /* reset the hardware and block queue progress */ - if (as->use_dma) { + if (as->use_dma) atmel_spi_stop_dma(host); - atmel_spi_release_dma(host); - if (IS_ENABLED(CONFIG_SOC_SAM_V4_V5)) { - dma_free_coherent(&pdev->dev, SPI_MAX_DMA_XFER, - as->addr_tx_bbuf, - as->dma_addr_tx_bbuf); - dma_free_coherent(&pdev->dev, SPI_MAX_DMA_XFER, - as->addr_rx_bbuf, - as->dma_addr_rx_bbuf); - } - } spin_lock_irq(&as->lock); spi_writel(as, CR, SPI_BIT(SWRST));