From 7446284023e8ef694fb392348185349c773eefb3 Mon Sep 17 00:00:00 2001 From: Khairul Anuar Romli Date: Tue, 26 Aug 2025 08:33:58 +0800 Subject: spi: cadence-quadspi: Implement refcount to handle unbind during busy driver support indirect read and indirect write operation with assumption no force device removal(unbind) operation. However force device removal(removal) is still available to root superuser. Unbinding driver during operation causes kernel crash. This changes ensure driver able to handle such operation for indirect read and indirect write by implementing refcount to track attached devices to the controller and gracefully wait and until attached devices remove operation completed before proceed with removal operation. Signed-off-by: Khairul Anuar Romli Reviewed-by: Matthew Gerlach Reviewed-by: Niravkumar L Rabara Link: https://patch.msgid.link/8704fd6bd2ff4d37bba4a0eacf5eba3ba001079e.1756168074.git.khairul.anuar.romli@altera.com Signed-off-by: Mark Brown --- drivers/spi/spi-cadence-quadspi.c | 33 +++++++++++++++++++++++++++++++++ 1 file changed, 33 insertions(+) (limited to 'drivers/spi/spi-cadence-quadspi.c') diff --git a/drivers/spi/spi-cadence-quadspi.c b/drivers/spi/spi-cadence-quadspi.c index 177f9a33f3a2..9bf823348cd3 100644 --- a/drivers/spi/spi-cadence-quadspi.c +++ b/drivers/spi/spi-cadence-quadspi.c @@ -108,6 +108,8 @@ struct cqspi_st { bool is_jh7110; /* Flag for StarFive JH7110 SoC */ bool disable_stig_mode; + refcount_t refcount; + refcount_t inflight_ops; const struct cqspi_driver_platdata *ddata; }; @@ -735,6 +737,9 @@ static int cqspi_indirect_read_execute(struct cqspi_flash_pdata *f_pdata, u8 *rxbuf_end = rxbuf + n_rx; int ret = 0; + if (!refcount_read(&cqspi->refcount)) + return -ENODEV; + writel(from_addr, reg_base + CQSPI_REG_INDIRECTRDSTARTADDR); writel(remaining, reg_base + CQSPI_REG_INDIRECTRDBYTES); @@ -1071,6 +1076,9 @@ static int cqspi_indirect_write_execute(struct cqspi_flash_pdata *f_pdata, unsigned int write_bytes; int ret; + if (!refcount_read(&cqspi->refcount)) + return -ENODEV; + writel(to_addr, reg_base + CQSPI_REG_INDIRECTWRSTARTADDR); writel(remaining, reg_base + CQSPI_REG_INDIRECTWRBYTES); @@ -1461,12 +1469,26 @@ static int cqspi_exec_mem_op(struct spi_mem *mem, const struct spi_mem_op *op) struct cqspi_st *cqspi = spi_controller_get_devdata(mem->spi->controller); struct device *dev = &cqspi->pdev->dev; + if (refcount_read(&cqspi->inflight_ops) == 0) + return -ENODEV; + ret = pm_runtime_resume_and_get(dev); if (ret) { dev_err(&mem->spi->dev, "resume failed with %d\n", ret); return ret; } + if (!refcount_read(&cqspi->refcount)) + return -EBUSY; + + refcount_inc(&cqspi->inflight_ops); + + if (!refcount_read(&cqspi->refcount)) { + if (refcount_read(&cqspi->inflight_ops)) + refcount_dec(&cqspi->inflight_ops); + return -EBUSY; + } + ret = cqspi_mem_process(mem, op); pm_runtime_put_autosuspend(dev); @@ -1474,6 +1496,9 @@ static int cqspi_exec_mem_op(struct spi_mem *mem, const struct spi_mem_op *op) if (ret) dev_err(&mem->spi->dev, "operation failed with %d\n", ret); + if (refcount_read(&cqspi->inflight_ops) > 1) + refcount_dec(&cqspi->inflight_ops); + return ret; } @@ -1925,6 +1950,9 @@ static int cqspi_probe(struct platform_device *pdev) } } + refcount_set(&cqspi->refcount, 1); + refcount_set(&cqspi->inflight_ops, 1); + ret = devm_request_irq(dev, irq, cqspi_irq_handler, 0, pdev->name, cqspi); if (ret) { @@ -1987,6 +2015,11 @@ static void cqspi_remove(struct platform_device *pdev) { struct cqspi_st *cqspi = platform_get_drvdata(pdev); + refcount_set(&cqspi->refcount, 0); + + if (!refcount_dec_and_test(&cqspi->inflight_ops)) + cqspi_wait_idle(cqspi); + spi_unregister_controller(cqspi->host); cqspi_controller_enable(cqspi, 0); -- cgit v1.2.3