linux-kernel - [PATCH] mmc: meson-gx: fix wrong conversion of __bf_shf to _

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Message-ID: <20240812115515.20158-1-ansuelsmth@gmail.com>
Date: Mon, 12 Aug 2024 13:55:10 +0200
From: Christian Marangi <ansuelsmth@...il.com>
To: Ulf Hansson <ulf.hansson@...aro.org>,
	Neil Armstrong <neil.armstrong@...aro.org>,
	Kevin Hilman <khilman@...libre.com>,
	Jerome Brunet <jbrunet@...libre.com>,
	Martin Blumenstingl <martin.blumenstingl@...glemail.com>,
	linux-mmc@...r.kernel.org,
	linux-arm-kernel@...ts.infradead.org,
	linux-amlogic@...ts.infradead.org,
	linux-kernel@...r.kernel.org
Cc: Christian Marangi <ansuelsmth@...il.com>,
	stable@...r.kernel.org
Subject: [PATCH] mmc: meson-gx: fix wrong conversion of __bf_shf to __ffs

Commit 795c633f6093 ("mmc: meson-gx: fix __ffsdi2 undefined on arm32")
changed __bf_shf to __ffs to fix a compile error on 32bit arch that have
problems with __ffsdi2. This comes from the fact that __bf_shf use
__builtin_ffsll and on 32bit __ffsdi2 is missing.

Problem is that __bf_shf is defined as

  #define __bf_shf(x) (__builtin_ffsll(x) - 1)

but the patch doesn't account for the - 1.

Fix this by using the __builtin_ffs and add the - 1 to reflect the
original implementation.

The commit also converted other entry of __bf_shf in the code but those
got dropped in later patches.

Fixes: 795c633f6093 ("mmc: meson-gx: fix __ffsdi2 undefined on arm32")
Signed-off-by: Christian Marangi <ansuelsmth@...il.com>
Cc: stable@...r.kernel.org # see patch description, needs adjustements for < 5.2
---
 drivers/mmc/host/meson-gx-mmc.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/mmc/host/meson-gx-mmc.c b/drivers/mmc/host/meson-gx-mmc.c
index c7c067b9415a..8f64083a08fa 100644
--- a/drivers/mmc/host/meson-gx-mmc.c
+++ b/drivers/mmc/host/meson-gx-mmc.c
@@ -464,7 +464,7 @@ static int meson_mmc_clk_init(struct meson_host *host)
 	init.num_parents = MUX_CLK_NUM_PARENTS;
 
 	mux->reg = host->regs + SD_EMMC_CLOCK;
-	mux->shift = __ffs(CLK_SRC_MASK);
+	mux->shift = __builtin_ffs(CLK_SRC_MASK) - 1;
 	mux->mask = CLK_SRC_MASK >> mux->shift;
 	mux->hw.init = &init;
 
@@ -486,7 +486,7 @@ static int meson_mmc_clk_init(struct meson_host *host)
 	init.num_parents = 1;
 
 	div->reg = host->regs + SD_EMMC_CLOCK;
-	div->shift = __ffs(CLK_DIV_MASK);
+	div->shift = __builtin_ffs(CLK_DIV_MASK) - 1;
 	div->width = __builtin_popcountl(CLK_DIV_MASK);
 	div->hw.init = &init;
 	div->flags = CLK_DIVIDER_ONE_BASED;
-- 
2.45.2