From 6b32d7474e9b833dc7fadc1b4d4f08af9bd87fde Mon Sep 17 00:00:00 2001 From: André Draszik Date: Tue, 30 Apr 2024 10:54:59 +0100 Subject: clk: samsung: gs101: mark some apm UASC and XIU clocks critical MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The system hangs when any of these clocks are turned off. With the introduction of pinctrl clock support [1], the approach taken in this clock driver for the APM clocks to rely solely on the clk_ignore_unused kernel command line option does not work anymore and the system hangs during boot. gout_apm_func is a parent clock to the clocks that are going to be handled by the pinctrl driver [2], namely gout_apm_apbif_gpio_alive_pclk and gout_apm_apbif_gpio_far_alive_pclk. It also is the parent to the clocks marked as critical in this commit here (and some others that aren't relevant for this commit)). This means that once the pinctrl driver decides to turn off clocks, the clock framework will subsequently turn off parent clocks of those pinctrl clocks if they have no (apparent) user. Since gout_apm_func is the parent, and since no drivers are hooked up to it or any of its other children, gout_apm_func will be turned off. This will cause the system to hang, as the clocks marked as critical in this commit stop having an input. We might have to add a driver for these clocks, but in the meantime let's just ensure they stay on even if siblings are turned off. For the avoidance of doubt: This commit doesn't mean that we can boot without clk_ignore_unused. Link: https://lore.kernel.org/r/20240426-samsung-pinctrl-busclock-v3-0-adb8664b8a7e@linaro.org [1] Link: https://lore.kernel.org/r/20240429-samsung-pinctrl-busclock-dts-v1-0-5e935179f3ca@linaro.org [2] Signed-off-by: André Draszik Reviewed-by: Tudor Ambarus Link: https://lore.kernel.org/r/20240430-gs101-apm-clocks-v1-1-b2e2335e84f5@linaro.org Signed-off-by: Krzysztof Kozlowski --- drivers/clk/samsung/clk-gs101.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/clk/samsung/clk-gs101.c b/drivers/clk/samsung/clk-gs101.c index 05129c3b2f68..e2a6a1992505 100644 --- a/drivers/clk/samsung/clk-gs101.c +++ b/drivers/clk/samsung/clk-gs101.c @@ -1896,16 +1896,16 @@ static const struct samsung_gate_clock apm_gate_clks[] __initconst = { CLK_CON_GAT_GOUT_BLK_APM_UID_UASC_G_SWD_IPCLKPORT_PCLK, 21, 0, 0), GATE(CLK_GOUT_APM_UASC_P_APM_ACLK, "gout_apm_uasc_p_apm_aclk", "gout_apm_func", - CLK_CON_GAT_GOUT_BLK_APM_UID_UASC_P_APM_IPCLKPORT_ACLK, 21, 0, 0), + CLK_CON_GAT_GOUT_BLK_APM_UID_UASC_P_APM_IPCLKPORT_ACLK, 21, CLK_IS_CRITICAL, 0), GATE(CLK_GOUT_APM_UASC_P_APM_PCLK, "gout_apm_uasc_p_apm_pclk", "gout_apm_func", - CLK_CON_GAT_GOUT_BLK_APM_UID_UASC_P_APM_IPCLKPORT_PCLK, 21, 0, 0), + CLK_CON_GAT_GOUT_BLK_APM_UID_UASC_P_APM_IPCLKPORT_PCLK, 21, CLK_IS_CRITICAL, 0), GATE(CLK_GOUT_APM_WDT_APM_PCLK, "gout_apm_wdt_apm_pclk", "gout_apm_func", CLK_CON_GAT_GOUT_BLK_APM_UID_WDT_APM_IPCLKPORT_PCLK, 21, 0, 0), GATE(CLK_GOUT_APM_XIU_DP_APM_ACLK, "gout_apm_xiu_dp_apm_aclk", "gout_apm_func", - CLK_CON_GAT_GOUT_BLK_APM_UID_XIU_DP_APM_IPCLKPORT_ACLK, 21, 0, 0), + CLK_CON_GAT_GOUT_BLK_APM_UID_XIU_DP_APM_IPCLKPORT_ACLK, 21, CLK_IS_CRITICAL, 0), }; static const struct samsung_cmu_info apm_cmu_info __initconst = { -- cgit v1.2.3