5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Itai Handler commit e922bad8b2d5028c51a096d083fea41cd0987154 upstream. The driver has no ->shutdown, and platform_drv_shutdown() has no fallback of its own. Unlike pci_device_shutdown(), which clears bus mastering when kexec_in_progress, nothing on the platform bus disarms a device that can still write to memory. The normal kexec path never calls ->suspend either, so the quiesce in zynqmp_qspi_suspend() is not reached. A controller that is still executing a DMA read may therefore keep writing to memory across a kexec. QSPIDMA_DST_ADDR still points at memory owned by the kernel that called kexec, DST_SIZE is non-zero and the flash is still clocked, so data can keep landing in RAM while the new kernel is being relocated, and after it has started executing. That destination is a physical address which means nothing to the new kernel, so the writes can corrupt whatever now occupies it: kernel text or data, page tables, or the initrd. Nothing reports an error and the resulting behaviour is undefined. This can be observed by reading GQSPI_EN (offset 0x114) and QSPIDMA_DST_ADDR/SIZE/STS/CTRL (offsets 0x800 to 0x80c) early in the new kernel, before the driver probes: without this patch GQSPI_EN reads 1 and QSPIDMA_DST_ADDR still points into the previous kernel's memory. Add a ->shutdown that stops the controller the way zynqmp_qspi_suspend() already does. spi_controller_suspend() stops the queue, waits for a message that is already executing and makes any later transfer fail with -ESHUTDOWN, so nothing can be cut short by the register write that follows. It may sleep, which is fine here: device_shutdown() runs in process context. Unlike ->suspend this cannot abort on error, because a controller left mastering the bus is worse than a truncated transfer, so a failure to drain is only logged. GQSPI_EN_OFST is then cleared, as zynqmp_qspi_remove() and zynqmp_qspi_suspend() already do. Skip that write only when pm_runtime_get_if_in_use() returns 0, i.e. runtime suspended: the clocks are gated, so the registers are unreachable and the controller cannot be mastering the bus. A negative return is not the same thing - it is what the CONFIG_PM=n stub always returns, and there probe() has enabled pclk and refclk for good, so the controller is running and must be stopped. Fixes: dfe11a11d523 ("spi: Add support for Zynq Ultrascale+ MPSoC GQSPI controller") Cc: stable@vger.kernel.org Signed-off-by: Itai Handler Link: https://patch.msgid.link/20260910174832.873352-1-itai.handler@gmail.com Signed-off-by: Mark Brown [ itai: context only - two differences from mainline here: the platform_driver callback is still spelled .remove_new, renamed back to .remove upstream by commit 494c3dc46776 ("spi: Switch back to struct platform_driver::remove()"); and zynqmp_qspi_of_match[] still sits between zynqmp_qspi_remove() and MODULE_DEVICE_TABLE(), hoisted to the top of the file upstream by commit 29f4d95b97bc ("spi: spi-zynqmp-gqspi: Add tap delay support for GQSPI controller on Versal platform"), so zynqmp_qspi_shutdown() is placed above it ] Signed-off-by: Itai Handler Signed-off-by: Sasha Levin --- drivers/spi/spi-zynqmp-gqspi.c | 34 ++++++++++++++++++++++++++++++++++ 1 file changed, 34 insertions(+) diff --git a/drivers/spi/spi-zynqmp-gqspi.c b/drivers/spi/spi-zynqmp-gqspi.c index 90060e5a314c1..590ecd79cb501 100644 --- a/drivers/spi/spi-zynqmp-gqspi.c +++ b/drivers/spi/spi-zynqmp-gqspi.c @@ -1236,6 +1236,39 @@ static void zynqmp_qspi_remove(struct platform_device *pdev) clk_disable_unprepare(xqspi->pclk); } +static void zynqmp_qspi_shutdown(struct platform_device *pdev) +{ + struct zynqmp_qspi *xqspi = platform_get_drvdata(pdev); + int ret; + + /* + * Stop the queue and reject any later transfer first, so the write + * below cannot cut into a message that is still being executed. + * Unlike ->suspend this cannot abort on error: a controller left + * mastering the bus is worse than a truncated transfer. + */ + ret = spi_controller_suspend(xqspi->ctlr); + if (ret) + dev_warn(&pdev->dev, "could not stop the queue: %d\n", ret); + + /* + * Only a runtime suspended controller can be left alone: its clocks + * are gated, so it cannot be mastering the bus, and its registers + * must not be accessed either. Any other answer means it may be + * running and has to be stopped. In particular, on a kernel built + * without runtime PM this returns -EINVAL, and there the clocks + * enabled in probe() are never gated at all. + */ + ret = pm_runtime_get_if_in_use(&pdev->dev); + if (!ret) + return; + + zynqmp_gqspi_write(xqspi, GQSPI_EN_OFST, 0x0); + + if (ret > 0) + pm_runtime_put_noidle(&pdev->dev); +} + static const struct of_device_id zynqmp_qspi_of_match[] = { { .compatible = "xlnx,zynqmp-qspi-1.0", }, { /* End of table */ } @@ -1246,6 +1279,7 @@ MODULE_DEVICE_TABLE(of, zynqmp_qspi_of_match); static struct platform_driver zynqmp_qspi_driver = { .probe = zynqmp_qspi_probe, .remove_new = zynqmp_qspi_remove, + .shutdown = zynqmp_qspi_shutdown, .driver = { .name = "zynqmp-qspi", .of_match_table = zynqmp_qspi_of_match, -- 2.53.0