From: Bartosz Golaszewski Date: Thu, 28 Mar 2019 10:38:06 +0000 (+0100) Subject: gpio: mockup: use simple_read_from_buffer() in debugfs read callback X-Git-Tag: v5.1-rc3~10^2^2 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=ce9fb53c72834646f26ecb2213e40e6876048f87;p=thirdparty%2Flinux.git gpio: mockup: use simple_read_from_buffer() in debugfs read callback Calling read() for a single byte read will return 2 currently. Use simple_read_from_buffer() which correctly handles all sizes. Fixes: 2a9e27408e12 ("gpio: mockup: rework debugfs interface") Reviewed-by: Mukesh Ojha Signed-off-by: Bartosz Golaszewski --- diff --git a/drivers/gpio/gpio-mockup.c b/drivers/gpio/gpio-mockup.c index 74ba8b1d71d87..b6a4efce7c928 100644 --- a/drivers/gpio/gpio-mockup.c +++ b/drivers/gpio/gpio-mockup.c @@ -204,10 +204,9 @@ static ssize_t gpio_mockup_debugfs_read(struct file *file, struct gpio_mockup_chip *chip; struct seq_file *sfile; struct gpio_chip *gc; - int val, rv, cnt; + int val, cnt; char buf[3]; - if (*ppos != 0) return 0; @@ -219,12 +218,7 @@ static ssize_t gpio_mockup_debugfs_read(struct file *file, val = gpio_mockup_get(gc, priv->offset); cnt = snprintf(buf, sizeof(buf), "%d\n", val); - rv = copy_to_user(usr_buf, buf, cnt); - if (rv) - return rv; - - *ppos += cnt; - return cnt; + return simple_read_from_buffer(usr_buf, size, ppos, buf, cnt); } static ssize_t gpio_mockup_debugfs_write(struct file *file,