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| author | Keerthy <j-keerthy@ti.com> | 2016-04-14 10:29:16 +0530 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-05-04 14:49:04 -0700 |
| commit | 2c776b98a8b3102b6d0a18827e8f60dcb3f679f3 (patch) | |
| tree | a43ca6f15903ea48c75a8d7384ae72f98877926d | |
| parent | 2126e3425ef520ab8133b4ff09fe7fff77149b07 (diff) | |
| download | linux-stable-2c776b98a8b3102b6d0a18827e8f60dcb3f679f3.tar.gz linux-stable-2c776b98a8b3102b6d0a18827e8f60dcb3f679f3.tar.bz2 linux-stable-2c776b98a8b3102b6d0a18827e8f60dcb3f679f3.zip | |
pinctrl: single: Fix pcs_parse_bits_in_pinctrl_entry to use __ffs than ffs
commit 56b367c0cd67d4c3006738e7dc9dda9273fd2bfe upstream.
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/pinctrl/pinctrl-single.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/drivers/pinctrl/pinctrl-single.c b/drivers/pinctrl/pinctrl-single.c index d24e5f1d1525..bd2e657163b8 100644 --- a/drivers/pinctrl/pinctrl-single.c +++ b/drivers/pinctrl/pinctrl-single.c @@ -1273,9 +1273,9 @@ 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; @@ -1844,7 +1844,7 @@ 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. */ |