From e2f1ada8e089dd5a331bcd8b88125ae2af8d188f Mon Sep 17 00:00:00 2001 From: Pratap Nirujogi Date: Fri, 20 Mar 2026 16:12:22 -0400 Subject: [PATCH] i2c: designware: amdisp: Fix resume-probe race condition issue Identified resume-probe race condition in kernel v7.0 with the commit 38fa29b01a6a ("i2c: designware: Combine the init functions"),but this issue existed from the beginning though not detected. The amdisp i2c device requires ISP to be in power-on state for probe to succeed. To meet this requirement, this device is added to genpd to control ISP power using runtime PM. The pm_runtime_get_sync() called before i2c_dw_probe() triggers PM resume, which powers on ISP and also invokes the amdisp i2c runtime resume before the probe completes resulting in this race condition and a NULL dereferencing issue in v7.0 Fix this race condition by using the genpd APIs directly during probe: - Call dev_pm_genpd_resume() to Power ON ISP before probe - Call dev_pm_genpd_suspend() to Power OFF ISP after probe - Set the device to suspended state with pm_runtime_set_suspended() - Enable runtime PM only after the device is fully initialized Fixes: d6263c468a761 ("i2c: amd-isp: Add ISP i2c-designware driver") Co-developed-by: Bin Du Signed-off-by: Bin Du Signed-off-by: Pratap Nirujogi Cc: # v6.16+ Acked-by: Mika Westerberg Reviewed-by: Mario Limonciello (AMD) Reviewed-by: Andy Shevchenko Signed-off-by: Andi Shyti Link: https://lore.kernel.org/r/20260320201302.3490570-1-pratap.nirujogi@amd.com --- drivers/i2c/busses/i2c-designware-amdisp.c | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-) diff --git a/drivers/i2c/busses/i2c-designware-amdisp.c b/drivers/i2c/busses/i2c-designware-amdisp.c index c48728ad9f6f..9f0ec0fae6f2 100644 --- a/drivers/i2c/busses/i2c-designware-amdisp.c +++ b/drivers/i2c/busses/i2c-designware-amdisp.c @@ -7,6 +7,7 @@ #include #include +#include #include #include @@ -76,22 +77,20 @@ static int amd_isp_dw_i2c_plat_probe(struct platform_device *pdev) device_enable_async_suspend(&pdev->dev); - pm_runtime_enable(&pdev->dev); - pm_runtime_get_sync(&pdev->dev); - + dev_pm_genpd_resume(&pdev->dev); ret = i2c_dw_probe(isp_i2c_dev); if (ret) { dev_err_probe(&pdev->dev, ret, "i2c_dw_probe failed\n"); goto error_release_rpm; } - - pm_runtime_put_sync(&pdev->dev); + dev_pm_genpd_suspend(&pdev->dev); + pm_runtime_set_suspended(&pdev->dev); + pm_runtime_enable(&pdev->dev); return 0; error_release_rpm: amd_isp_dw_i2c_plat_pm_cleanup(isp_i2c_dev); - pm_runtime_put_sync(&pdev->dev); return ret; }