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authorAdrian Betschart <adrian.betschart@cinemaone.ch>2026-09-11 17:13:14 +0200
committerAlex Deucher <alexander.deucher@amd.com>2026-10-01 17:18:05 -0400
commit106b4a2a78b2a2f14885604891957b84bba502db (patch)
tree5d40eef2428fb1a4791ab46a4b19091a5910eac2 /drivers/clocksource/timer-riscv.c
downloadlinux-stable-106b4a2a78b2a2f14885604891957b84bba502db.tar.gz
linux-stable-106b4a2a78b2a2f14885604891957b84bba502db.zip
drm/amd/display: Try RGB before YCbCr 4:4:4 in stream validationgrafted
amdgpu_dm_create_validate_stream_for_sink() walks encoding_order[] and uses the first encoding that validates. YCbCr 4:4:4 is listed before RGB, so an HDMI sink that advertises 4:4:4 gets YCbCr 4:4:4 whenever the "color format" property is left at AUTO, even though RGB fits the same link. That contradicts the documented AUTO behaviour for HDMI in enum drm_connector_color_format (RGB, falling back to YCbCr 4:2:0 only when the bandwidth is not available or the mode is 4:2:0-only), which the amdgpu implementation of the property also describes. It also leaves the "Broadcast RGB" property without effect on such sinks, since the quantization range it selects only applies to RGB output. Try RGB first. The mask still holds every encoding the sink supports, so a mode that cannot carry RGB falls back exactly as before. For reference, v7.2 picked RGB here unless YCbCr 4:4:4 was forced through debugfs, while earlier kernels picked YCbCr 4:4:4 for any HDMI sink that advertised it. Fixes: 0b0ff65d3ca1 ("drm/amd/display: Refactor stream validation") Suggested-by: Adolfo Rodrigues <adolfotregosa@gmail.com> Assisted-by: Claude Code:claude-fable-5-1 Signed-off-by: Adrian Betschart <adrian.betschart@cinemaone.ch> Reviewed-by: Fangzhi Zuo <jerry.zuo@amd.com> Tested-by: Adolfo Rodrigues <adolfotregosa@gmail.com> Tested-by: Daniel Wheeler <daniel.wheeler@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> (cherry picked from commit 7de432bc753133764dc40d37f9388da56de251e7)
Diffstat (limited to 'drivers/clocksource/timer-riscv.c')
-rw-r--r--drivers/clocksource/timer-riscv.c250
1 files changed, 250 insertions, 0 deletions
diff --git a/drivers/clocksource/timer-riscv.c b/drivers/clocksource/timer-riscv.c
new file mode 100644
index 000000000..b310e6721
--- /dev/null
+++ b/drivers/clocksource/timer-riscv.c
@@ -0,0 +1,250 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2012 Regents of the University of California
+ * Copyright (C) 2017 SiFive
+ *
+ * All RISC-V systems have a timer attached to every hart. These timers can
+ * either be read from the "time" and "timeh" CSRs, and can use the SBI to
+ * setup events, or directly accessed using MMIO registers.
+ */
+
+#define pr_fmt(fmt) "riscv-timer: " fmt
+
+#include <linux/acpi.h>
+#include <linux/clocksource.h>
+#include <linux/clockchips.h>
+#include <linux/cpu.h>
+#include <linux/delay.h>
+#include <linux/irq.h>
+#include <linux/irqdomain.h>
+#include <linux/module.h>
+#include <linux/sched_clock.h>
+#include <linux/io-64-nonatomic-lo-hi.h>
+#include <linux/interrupt.h>
+#include <linux/of_irq.h>
+#include <linux/limits.h>
+#include <clocksource/timer-riscv.h>
+#include <asm/smp.h>
+#include <asm/cpufeature.h>
+#include <asm/sbi.h>
+#include <asm/timex.h>
+
+static DEFINE_STATIC_KEY_FALSE(riscv_sstc_available);
+static bool riscv_timer_cannot_wake_cpu;
+
+static void riscv_clock_event_stop(void)
+{
+ if (static_branch_likely(&riscv_sstc_available)) {
+ csr_write(CSR_STIMECMP, ULONG_MAX);
+ if (IS_ENABLED(CONFIG_32BIT))
+ csr_write(CSR_STIMECMPH, ULONG_MAX);
+ } else {
+ sbi_set_timer(U64_MAX);
+ }
+}
+
+static int riscv_clock_next_event(unsigned long delta,
+ struct clock_event_device *ce)
+{
+ u64 next_tval = get_cycles64() + delta;
+
+ if (static_branch_likely(&riscv_sstc_available)) {
+#if defined(CONFIG_32BIT)
+ csr_write(CSR_STIMECMP, ULONG_MAX);
+ csr_write(CSR_STIMECMPH, next_tval >> 32);
+ csr_write(CSR_STIMECMP, next_tval & 0xFFFFFFFF);
+#else
+ csr_write(CSR_STIMECMP, next_tval);
+#endif
+ } else
+ sbi_set_timer(next_tval);
+
+ return 0;
+}
+
+static int riscv_clock_shutdown(struct clock_event_device *evt)
+{
+ riscv_clock_event_stop();
+ return 0;
+}
+
+static unsigned int riscv_clock_event_irq;
+static DEFINE_PER_CPU(struct clock_event_device, riscv_clock_event) = {
+ .name = "riscv_timer_clockevent",
+ .features = CLOCK_EVT_FEAT_ONESHOT,
+ .rating = 100,
+ .set_next_event = riscv_clock_next_event,
+ .set_state_shutdown = riscv_clock_shutdown,
+};
+
+/*
+ * It is guaranteed that all the timers across all the harts are synchronized
+ * within one tick of each other, so while this could technically go
+ * backwards when hopping between CPUs, practically it won't happen.
+ */
+static unsigned long long riscv_clocksource_rdtime(struct clocksource *cs)
+{
+ return get_cycles64();
+}
+
+static u64 notrace riscv_sched_clock(void)
+{
+ return get_cycles64();
+}
+
+static struct clocksource riscv_clocksource = {
+ .name = "riscv_clocksource",
+ .rating = 400,
+ .mask = CLOCKSOURCE_MASK(64),
+ .flags = CLOCK_SOURCE_IS_CONTINUOUS,
+ .read = riscv_clocksource_rdtime,
+ .vdso_clock_mode = VDSO_CLOCKMODE_ARCHTIMER,
+};
+
+static int riscv_timer_starting_cpu(unsigned int cpu)
+{
+ struct clock_event_device *ce = per_cpu_ptr(&riscv_clock_event, cpu);
+
+ /* Clear timer interrupt */
+ riscv_clock_event_stop();
+
+ ce->cpumask = cpumask_of(cpu);
+ ce->irq = riscv_clock_event_irq;
+ if (riscv_timer_cannot_wake_cpu)
+ ce->features |= CLOCK_EVT_FEAT_C3STOP;
+ if (static_branch_likely(&riscv_sstc_available))
+ ce->rating = 450;
+ clockevents_config_and_register(ce, riscv_timebase, 100, ULONG_MAX);
+
+ enable_percpu_irq(riscv_clock_event_irq,
+ irq_get_trigger_type(riscv_clock_event_irq));
+ return 0;
+}
+
+static int riscv_timer_dying_cpu(unsigned int cpu)
+{
+ /*
+ * Stop the timer when the cpu is going to be offline otherwise
+ * the timer interrupt may be pending while performing power-down.
+ */
+ riscv_clock_event_stop();
+ disable_percpu_irq(riscv_clock_event_irq);
+
+ return 0;
+}
+
+void riscv_cs_get_mult_shift(u32 *mult, u32 *shift)
+{
+ *mult = riscv_clocksource.mult;
+ *shift = riscv_clocksource.shift;
+}
+EXPORT_SYMBOL_GPL(riscv_cs_get_mult_shift);
+
+/* called directly from the low-level interrupt handler */
+static irqreturn_t riscv_timer_interrupt(int irq, void *dev_id)
+{
+ struct clock_event_device *evdev = this_cpu_ptr(&riscv_clock_event);
+
+ riscv_clock_event_stop();
+ evdev->event_handler(evdev);
+
+ return IRQ_HANDLED;
+}
+
+static int __init riscv_timer_init_common(void)
+{
+ int error;
+ struct irq_domain *domain;
+ struct fwnode_handle *intc_fwnode = riscv_get_intc_hwnode();
+
+ domain = irq_find_matching_fwnode(intc_fwnode, DOMAIN_BUS_ANY);
+ if (!domain) {
+ pr_err("Failed to find irq_domain for INTC node [%pfwP]\n",
+ intc_fwnode);
+ return -ENODEV;
+ }
+
+ riscv_clock_event_irq = irq_create_mapping(domain, RV_IRQ_TIMER);
+ if (!riscv_clock_event_irq) {
+ pr_err("Failed to map timer interrupt for node [%pfwP]\n", intc_fwnode);
+ return -ENODEV;
+ }
+
+ error = clocksource_register_hz(&riscv_clocksource, riscv_timebase);
+ if (error) {
+ pr_err("RISCV timer registration failed [%d]\n", error);
+ return error;
+ }
+
+ sched_clock_register(riscv_sched_clock, 64, riscv_timebase);
+
+ error = request_percpu_irq(riscv_clock_event_irq,
+ riscv_timer_interrupt,
+ "riscv-timer", &riscv_clock_event);
+ if (error) {
+ pr_err("registering percpu irq failed [%d]\n", error);
+ return error;
+ }
+
+ if (riscv_isa_extension_available(NULL, SSTC)) {
+ pr_info("Timer interrupt in S-mode is available via sstc extension\n");
+ static_branch_enable(&riscv_sstc_available);
+ }
+
+ error = cpuhp_setup_state(CPUHP_AP_RISCV_TIMER_STARTING,
+ "clockevents/riscv/timer:starting",
+ riscv_timer_starting_cpu, riscv_timer_dying_cpu);
+ if (error)
+ pr_err("cpu hp setup state failed for RISCV timer [%d]\n",
+ error);
+
+ return error;
+}
+
+static int __init riscv_timer_init_dt(struct device_node *n)
+{
+ int cpuid, error;
+ unsigned long hartid;
+ struct device_node *child;
+
+ error = riscv_of_processor_hartid(n, &hartid);
+ if (error < 0) {
+ pr_warn("Invalid hartid for node [%pOF] error = [%lu]\n",
+ n, hartid);
+ return error;
+ }
+
+ cpuid = riscv_hartid_to_cpuid(hartid);
+ if (cpuid < 0) {
+ pr_warn("Invalid cpuid for hartid [%lu]\n", hartid);
+ return cpuid;
+ }
+
+ if (cpuid != smp_processor_id())
+ return 0;
+
+ child = of_find_compatible_node(NULL, NULL, "riscv,timer");
+ if (child) {
+ riscv_timer_cannot_wake_cpu = of_property_read_bool(child,
+ "riscv,timer-cannot-wake-cpu");
+ of_node_put(child);
+ }
+
+ return riscv_timer_init_common();
+}
+
+TIMER_OF_DECLARE(riscv_timer, "riscv", riscv_timer_init_dt);
+
+#ifdef CONFIG_ACPI
+static int __init riscv_timer_acpi_init(struct acpi_table_header *table)
+{
+ struct acpi_table_rhct *rhct = (struct acpi_table_rhct *)table;
+
+ riscv_timer_cannot_wake_cpu = rhct->flags & ACPI_RHCT_TIMER_CANNOT_WAKEUP_CPU;
+
+ return riscv_timer_init_common();
+}
+
+TIMER_ACPI_DECLARE(aclint_mtimer, ACPI_SIG_RHCT, riscv_timer_acpi_init);
+
+#endif