From ea408a05dc8f18b4a184b88d6e19d2fd1acc1527 Mon Sep 17 00:00:00 2001 From: Fan Wu Date: Sun, 19 Jul 2026 01:00:14 +0000 Subject: [PATCH] spi: davinci: switch to managed controller allocation The controller is allocated with the non-managed spi_alloc_host() while the interrupt is registered with devm_request_threaded_irq(). During removal, spi_bitbang_stop() only unregisters the controller; the subsequent spi_controller_put() then frees the controller together with its embedded davinci_spi devdata, which is the IRQ handler's dev_id. The devm_request_threaded_irq() release action (free_irq()), which drains the handler, does not run until after .remove() returns. A late or latched interrupt can therefore reach davinci_spi_irq() and dereference already-freed memory. Switch to devm_spi_alloc_host() so that the devres LIFO order releases the controller only after free_irq() has drained the handler, and drop the now-redundant spi_controller_put() from .remove(). The probe error path is simplified to direct returns. The clock is acquired with devm_clk_get_enabled(), which is registered after the IRQ and thus released before it by the devres LIFO order. Drain the interrupt explicitly with devm_free_irq() before disabling the controller so that a late interrupt cannot access the registers of a clock-gated controller. This issue was found by an in-house static analysis tool. Fixes: 5b3bb5963ff2 ("spi: davinci: Use devm_*() functions") Assisted-by: Codex:gpt-5.6 Signed-off-by: Fan Wu Link: https://patch.msgid.link/20260719010014.3163356-2-fanwu01@zju.edu.cn Signed-off-by: Mark Brown --- drivers/spi/spi-davinci.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/drivers/spi/spi-davinci.c b/drivers/spi/spi-davinci.c index da7f2ae3a570..087735ed9c80 100644 --- a/drivers/spi/spi-davinci.c +++ b/drivers/spi/spi-davinci.c @@ -928,7 +928,7 @@ static int davinci_spi_probe(struct platform_device *pdev) int ret = 0; u32 spipc0; - host = spi_alloc_host(&pdev->dev, sizeof(struct davinci_spi)); + host = devm_spi_alloc_host(&pdev->dev, sizeof(struct davinci_spi)); if (host == NULL) { ret = -ENOMEM; goto err; @@ -1057,7 +1057,6 @@ static int davinci_spi_probe(struct platform_device *pdev) dma_release_channel(dspi->dma_tx); } free_host: - spi_controller_put(host); err: return ret; } @@ -1081,6 +1080,8 @@ static void davinci_spi_remove(struct platform_device *pdev) spi_bitbang_stop(&dspi->bitbang); + devm_free_irq(&pdev->dev, dspi->irq, dspi); + /* This bit needs to be cleared to disable dpsi->clk */ clear_io_bits(dspi->base + SPIGCR1, SPIGCR1_POWERDOWN_MASK); @@ -1088,8 +1089,6 @@ static void davinci_spi_remove(struct platform_device *pdev) dma_release_channel(dspi->dma_rx); dma_release_channel(dspi->dma_tx); } - - spi_controller_put(host); } static struct platform_driver davinci_spi_driver = {