[PATCH v6 5/6] spmi: apple: lock around FIFOs
From: Sasha Finkelstein <k@chaosmail.tech>
Date: 2026-08-16 10:26:45
Also in:
asahi, linux-devicetree, lkml
Subsystem:
arm/apple machine support, spmi subsystem, the rest · Maintainers:
Sven Peter, Janne Grunau, Stephen Boyd, Linus Torvalds
From: Alba Mendez <redacted> The driver was missing locking around register interactions. Signed-off-by: Alba Mendez <redacted> Reviewed-by: Janne Grunau <j@jannau.net> Signed-off-by: Sasha Finkelstein <k@chaosmail.tech> --- drivers/spmi/spmi-apple-controller.c | 5 +++++ 1 file changed, 5 insertions(+)
diff --git a/drivers/spmi/spmi-apple-controller.c b/drivers/spmi/spmi-apple-controller.c
index 9843dc871d6c..fabccd25aa0d 100644
--- a/drivers/spmi/spmi-apple-controller.c
+++ b/drivers/spmi/spmi-apple-controller.c@@ -16,6 +16,7 @@ #include <linux/io.h> #include <linux/iopoll.h> #include <linux/module.h> +#include <linux/mutex.h> #include <linux/platform_device.h> #include <linux/spmi.h>
@@ -39,6 +40,7 @@ struct apple_spmi { void __iomem *regs; + struct mutex fifo_lock; bool prev_fail; };
@@ -78,6 +80,8 @@ static int spmi_raw_cmd(struct spmi_controller *ctrl, u8 opc, u8 sid, u16 param, size_t i = 0, j; int ret; + guard(mutex)(&spmi->fifo_lock); + if (spmi->prev_fail) { writel(SPMI_ACT_FIFO_FLUSH, spmi->regs + SPMI_ACT_REG); spmi->prev_fail = false;
@@ -195,6 +199,7 @@ static int apple_spmi_probe(struct platform_device *pdev) return -ENOMEM; spmi = spmi_controller_get_drvdata(ctrl); + mutex_init(&spmi->fifo_lock); spmi->regs = devm_platform_ioremap_resource(pdev, 0); if (IS_ERR(spmi->regs))
--
2.55.0