This is a note to let you know that I've just added the patch titled
clk: renesas: rzg2l: Lock around writes to mux register
to the 6.5-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
clk-renesas-rzg2l-lock-around-writes-to-mux-register.patch
and it can be found in the queue-6.5 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 54252d2e3b99b1afb87ca15ed57f9db6b53fb814
Author: Claudiu Beznea <claudiu.beznea.uj@xxxxxxxxxxxxxx>
Date: Fri Sep 29 08:38:50 2023 +0300
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 <claudiu.beznea.uj@xxxxxxxxxxxxxx>
Reviewed-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
Link: https://lore.kernel.org/r/20230929053915.1530607-4-claudiu.beznea@xxxxxxxxxxxxxx
Signed-off-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/clk/renesas/rzg2l-cpg.c b/drivers/clk/renesas/rzg2l-cpg.c
index 7245a34d43e0b..7be098315899c 100644
--- a/drivers/clk/renesas/rzg2l-cpg.c
+++ b/drivers/clk/renesas/rzg2l-cpg.c
@@ -196,6 +196,7 @@ 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;
/*
@@ -211,23 +212,25 @@ 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 6cee9e56acc72..91e9c2569f801 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))
