From e050f2fbcdbba4f73558d332d5cd78f8b329c86f Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Ma=C3=ADra=20Canal?= Date: Wed, 19 Aug 2026 11:16:45 -0300 Subject: [PATCH] clk: bcm: rpi: Restore the requested rate when preparing a clock MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Lowering the rate on unprepare writes to the firmware directly, so the rate the clock framework has cached keeps describing a state the hardware is no longer in. Nothing puts that rate back. A consumer that requests the same rate it had requested before the clock was unprepared is short-circuited by clk_core_set_rate_nolock(), which skips clocks that are already at the requested rate, so .set_rate is never reached. The clock is re-enabled at the rate unprepare left behind, and neither the consumer nor the framework has any indication that the request had no effect. Restore the rate the framework last resolved when preparing a clock, so that lowering the rate on unprepare stays invisible to consumers. Fixes: 0276d66986d0 ("clk: bcm: rpi: Manage clock rate in prepare/unprepare callbacks") Signed-off-by: Maíra Canal --- drivers/clk/bcm/clk-raspberrypi.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/clk/bcm/clk-raspberrypi.c b/drivers/clk/bcm/clk-raspberrypi.c index b19b55129f4f88..6076f1b91065b9 100644 --- a/drivers/clk/bcm/clk-raspberrypi.c +++ b/drivers/clk/bcm/clk-raspberrypi.c @@ -306,8 +306,14 @@ static int raspberrypi_fw_prepare(struct clk_hw *hw) return ret; } + /* + * Set the clock rate to the maximum possible rate or restore the rate + * the consumer requested. + */ if (variant->maximize) ret = raspberrypi_fw_set_rate(hw, variant->max_rate, 0); + else + ret = raspberrypi_fw_set_rate(hw, clk_hw_get_rate(hw), 0); return ret; }