Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
Pre-existing issues:
- [High] Early HPD interrupt can cause a NULL pointer dereference of `hdmi->bridge.dev` if it fires before `drm_bridge_attach` completes.
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commit 1a1229643b989df67626f64f580add186cebd6ed
Author: Michal Wilczynski [off-list ref]
drm/bridge: inno-hdmi: Allow the register map to come from a parent
On some SoCs the HDMI controller does not own its register window. The
StarFive JH7110 documents one 64 KB block, u0_hdmitx, that holds both
the controller and the PHY, so the parent device maps it and owns the
regmap while the two children share it.
quoted hunk ↗ jump to hunk
diff --git a/drivers/gpu/drm/bridge/inno-hdmi.c b/drivers/gpu/drm/bridge/inno-hdmi.c
index aab474740f7f5..8bd7717611804 100644
--- a/drivers/gpu/drm/bridge/inno-hdmi.c
+++ b/drivers/gpu/drm/bridge/inno-hdmi.c
[ ... ]
quoted hunk ↗ jump to hunk
@@ -1095,9 +1110,19 @@ struct inno_hdmi *inno_hdmi_probe(struct platform_device *pdev,
hdmi->dev = dev;
hdmi->plat_data = plat_data;
- hdmi->regs = devm_platform_ioremap_resource(pdev, 0);
- if (IS_ERR(hdmi->regs))
- return ERR_CAST(hdmi->regs);
+ /*
+ * On platforms where the controller shares a register space with
+ * other blocks, the parent owns the regmap. Fall back to mapping
+ * our own resource where it does not.
+ */
+ if (dev->parent)
+ hdmi->regmap = dev_get_regmap(dev->parent, NULL);
+
+ if (!hdmi->regmap) {
+ hdmi->regs = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(hdmi->regs))
+ return ERR_CAST(hdmi->regs);
+ }
hdmi->pclk = devm_clk_get_enabled(hdmi->dev, "pclk");
if (IS_ERR(hdmi->pclk)) {
[Severity: High]
This is a pre-existing issue, but could this code trigger a NULL pointer
dereference if the hotplug interrupt fires early?
Looking at the rest of inno_hdmi_probe(), the hardware interrupt is unmuted
in inno_hdmi_init_hw(), and then the handler is registered:
inno_hdmi_init_hw(hdmi);
...
ret = devm_request_threaded_irq(dev, irq, inno_hdmi_hardirq,
inno_hdmi_irq, IRQF_SHARED,
dev_name(dev), hdmi);
If a cable is already connected or plugged in at this exact moment, the
interrupt can fire immediately. The threaded handler inno_hdmi_irq() will
then execute:
drm_helper_hpd_irq_event(hdmi->bridge.dev);
However, hdmi->bridge.dev appears to be NULL at this point, as it is only
populated later when the upstream display controller calls
drm_bridge_attach().
Is there something preventing this race condition, or should the IRQ handler
registration be deferred?
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Sashiko AI review · https://sashiko.dev/#/patchset/20260904-jh7110-clean-send-v3-0-484f9ae72715@samsung.com?part=8
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