From f92905170cfa59a86958d94553b959797713dc1b Mon Sep 17 00:00:00 2001 From: Claudiu Beznea Date: Fri, 29 Sep 2023 08:38:50 +0300 Subject: [PATCH] clk: renesas: rzg2l: Lock around writes to mux register [ Upstream commit d2692ed490e680a41401cef879adebcfafb4298f ] The SD MUX output (SD0) is further divided by 4 in G2{L,UL}. The divided clock is SD0_DIV4. SD0_DIV4 is registered with CLK_SET_RATE_PARENT which means a rate request for it is propagated to the MUX and could reach rzg2l_cpg_sd_clk_mux_set_parent() concurrently with the users of SD0. Add proper locking to avoid concurrent accesses on SD MUX set rate registers. Fixes: eaff33646f4cb ("clk: renesas: rzg2l: Add SDHI clk mux support") Signed-off-by: Claudiu Beznea Reviewed-by: Geert Uytterhoeven Link: https://lore.kernel.org/r/20230929053915.1530607-4-claudiu.beznea@bp.renesas.com Signed-off-by: Geert Uytterhoeven Signed-off-by: Sasha Levin --- drivers/clk/renesas/rzg2l-cpg.c | 23 +++++++++++++---------- drivers/clk/renesas/rzg2l-cpg.h | 2 +- 2 files changed, 14 insertions(+), 11 deletions(-) diff --git a/drivers/clk/renesas/rzg2l-cpg.c b/drivers/clk/renesas/rzg2l-cpg.c index 9d25f7d..4c1f388 100644 --- a/drivers/clk/renesas/rzg2l-cpg.c +++ b/drivers/clk/renesas/rzg2l-cpg.c @@ -189,6 +189,7 @@ static int rzg2l_cpg_sd_clk_mux_set_parent(struct clk_hw *hw, u8 index) u32 shift = GET_SHIFT(hwdata->conf); const u32 clk_src_266 = 2; u32 msk, val, bitmask; + unsigned long flags; int ret; /* @@ -204,23 +205,25 @@ static int rzg2l_cpg_sd_clk_mux_set_parent(struct clk_hw *hw, u8 index) */ bitmask = (GENMASK(GET_WIDTH(hwdata->conf) - 1, 0) << shift) << 16; msk = off ? CPG_CLKSTATUS_SELSDHI1_STS : CPG_CLKSTATUS_SELSDHI0_STS; + spin_lock_irqsave(&priv->rmw_lock, flags); if (index != clk_src_266) { writel(bitmask | ((clk_src_266 + 1) << shift), priv->base + off); - ret = readl_poll_timeout(priv->base + CPG_CLKSTATUS, val, - !(val & msk), 100, - CPG_SDHI_CLK_SWITCH_STATUS_TIMEOUT_US); - if (ret) { - dev_err(priv->dev, "failed to switch clk source\n"); - return ret; - } + ret = readl_poll_timeout_atomic(priv->base + CPG_CLKSTATUS, val, + !(val & msk), 10, + CPG_SDHI_CLK_SWITCH_STATUS_TIMEOUT_US); + if (ret) + goto unlock; } writel(bitmask | ((index + 1) << shift), priv->base + off); - ret = readl_poll_timeout(priv->base + CPG_CLKSTATUS, val, - !(val & msk), 100, - CPG_SDHI_CLK_SWITCH_STATUS_TIMEOUT_US); + ret = readl_poll_timeout_atomic(priv->base + CPG_CLKSTATUS, val, + !(val & msk), 10, + CPG_SDHI_CLK_SWITCH_STATUS_TIMEOUT_US); +unlock: + spin_unlock_irqrestore(&priv->rmw_lock, flags); + if (ret) dev_err(priv->dev, "failed to switch clk source\n"); diff --git a/drivers/clk/renesas/rzg2l-cpg.h b/drivers/clk/renesas/rzg2l-cpg.h index 6cee9e5..91e9c25 100644 --- a/drivers/clk/renesas/rzg2l-cpg.h +++ b/drivers/clk/renesas/rzg2l-cpg.h @@ -43,7 +43,7 @@ #define CPG_CLKSTATUS_SELSDHI0_STS BIT(28) #define CPG_CLKSTATUS_SELSDHI1_STS BIT(29) -#define CPG_SDHI_CLK_SWITCH_STATUS_TIMEOUT_US 20000 +#define CPG_SDHI_CLK_SWITCH_STATUS_TIMEOUT_US 200 /* n = 0/1/2 for PLL1/4/6 */ #define CPG_SAMPLL_CLK1(n) (0x04 + (16 * n)) -- 2.7.4