rtc: cmos: Fix return value of nvmem callbacks

commit 1c184baccf0d5e2ef4cc1562261d0e48508a1c2b upstream.

Read/write callbacks registered with nvmem core expect 0 to be returned
on success and a negative value to be returned on failure.

cmos_nvram_read()/cmos_nvram_write() currently return the number of
bytes read or written, fix to return 0 on success and -EIO incase number
of bytes requested was not read or written.

Fixes: 8b5b7958fd ("rtc: cmos: use generic nvmem")
Cc: stable@vger.kernel.org
Signed-off-by: Joy Chakraborty <joychakr@google.com>
Reviewed-by: Dan Carpenter <dan.carpenter@linaro.org>
Link: https://lore.kernel.org/r/20240612083635.1253039-1-joychakr@google.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Joy Chakraborty 2024-06-12 08:36:35 +00:00 committed by Greg Kroah-Hartman
parent ab14e199b9
commit 13749b8d49
1 changed files with 4 additions and 6 deletions

View File

@ -643,11 +643,10 @@ static int cmos_nvram_read(void *priv, unsigned int off, void *val,
size_t count)
{
unsigned char *buf = val;
int retval;
off += NVRAM_OFFSET;
spin_lock_irq(&rtc_lock);
for (retval = 0; count; count--, off++, retval++) {
for (; count; count--, off++) {
if (off < 128)
*buf++ = CMOS_READ(off);
else if (can_bank2)
@ -657,7 +656,7 @@ static int cmos_nvram_read(void *priv, unsigned int off, void *val,
}
spin_unlock_irq(&rtc_lock);
return retval;
return count ? -EIO : 0;
}
static int cmos_nvram_write(void *priv, unsigned int off, void *val,
@ -665,7 +664,6 @@ static int cmos_nvram_write(void *priv, unsigned int off, void *val,
{
struct cmos_rtc *cmos = priv;
unsigned char *buf = val;
int retval;
/* NOTE: on at least PCs and Ataris, the boot firmware uses a
* checksum on part of the NVRAM data. That's currently ignored
@ -674,7 +672,7 @@ static int cmos_nvram_write(void *priv, unsigned int off, void *val,
*/
off += NVRAM_OFFSET;
spin_lock_irq(&rtc_lock);
for (retval = 0; count; count--, off++, retval++) {
for (; count; count--, off++) {
/* don't trash RTC registers */
if (off == cmos->day_alrm
|| off == cmos->mon_alrm
@ -689,7 +687,7 @@ static int cmos_nvram_write(void *priv, unsigned int off, void *val,
}
spin_unlock_irq(&rtc_lock);
return retval;
return count ? -EIO : 0;
}
/*----------------------------------------------------------------*/