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authorKeerthy <j-keerthy@ti.com>2016-04-14 10:29:16 +0530
committerLinus Walleij <linus.walleij@linaro.org>2016-04-15 11:26:55 +0200
commit56b367c0cd67d4c3006738e7dc9dda9273fd2bfe (patch)
tree047fa9663a42d64c1f2677f150172c0e82cb1cea
parent5fedbb923936174ab4d1d5cc92bca1cf6b2e0ca2 (diff)
downloadlinux-sh-56b367c0cd67d4c3006738e7dc9dda9273fd2bfe.tar.gz
pinctrl: single: Fix pcs_parse_bits_in_pinctrl_entry to use __ffs than ffs
pcs_parse_bits_in_pinctrl_entry uses ffs which gives bit indices ranging from 1 to MAX. This leads to a corner case where we try to request the pin number = MAX and fails. bit_pos value is being calculted using ffs. pin_num_from_lsb uses bit_pos value. pins array is populated with: pin + pin_num_from_lsb. The above is 1 more than usual bit indices as bit_pos uses ffs to compute first set bit. Hence the last of the pins array is populated with the MAX value and not MAX - 1 which causes error when we call pin_request. mask_pos is rightly calculated as ((pcs->fmask) << (bit_pos - 1)) Consequently val_pos and submask are correct. Hence use __ffs which gives (ffs(x) - 1) as the first bit set. fixes: 4e7e8017a8 ("pinctrl: pinctrl-single: enhance to configure multiple pins of different modules") Signed-off-by: Keerthy <j-keerthy@ti.com> Acked-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
-rw-r--r--drivers/pinctrl/pinctrl-single.c6
1 files changed, 3 insertions, 3 deletions
diff --git a/drivers/pinctrl/pinctrl-single.c b/drivers/pinctrl/pinctrl-single.c
index fb126d56ad40..cf9bafa10acf 100644
--- a/drivers/pinctrl/pinctrl-single.c
+++ b/drivers/pinctrl/pinctrl-single.c
@@ -1280,9 +1280,9 @@ static int pcs_parse_bits_in_pinctrl_entry(struct pcs_device *pcs,
/* Parse pins in each row from LSB */
while (mask) {
- bit_pos = ffs(mask);
+ bit_pos = __ffs(mask);
pin_num_from_lsb = bit_pos / pcs->bits_per_pin;
- mask_pos = ((pcs->fmask) << (bit_pos - 1));
+ mask_pos = ((pcs->fmask) << bit_pos);
val_pos = val & mask_pos;
submask = mask & mask_pos;
@@ -1852,7 +1852,7 @@ static int pcs_probe(struct platform_device *pdev)
ret = of_property_read_u32(np, "pinctrl-single,function-mask",
&pcs->fmask);
if (!ret) {
- pcs->fshift = ffs(pcs->fmask) - 1;
+ pcs->fshift = __ffs(pcs->fmask);
pcs->fmax = pcs->fmask >> pcs->fshift;
} else {
/* If mask property doesn't exist, function mux is invalid. */