From: Joy Chakraborty <joychakr@xxxxxxxxxx>
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: 8b5b7958fd1c ("rtc: cmos: use generic nvmem")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Joy Chakraborty <joychakr@xxxxxxxxxx>
Reviewed-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20240612083635.1253039-1-joychakr@xxxxxxxxxx
Signed-off-by: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/rtc/rtc-cmos.c | 10 ++++------
1 file changed, 4 insertions(+), 6 deletions(-)
--- a/drivers/rtc/rtc-cmos.c
+++ b/drivers/rtc/rtc-cmos.c
@@ -601,11 +601,10 @@ static int cmos_nvram_read(void *priv, u
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)
@@ -615,7 +614,7 @@ static int cmos_nvram_read(void *priv, u
}
spin_unlock_irq(&rtc_lock);
- return retval;
+ return count ? -EIO : 0;
}
static int cmos_nvram_write(void *priv, unsigned int off, void *val,
@@ -623,7 +622,6 @@ static int cmos_nvram_write(void *priv,
{
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
@@ -632,7 +630,7 @@ static int cmos_nvram_write(void *priv,
*/
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
@@ -647,7 +645,7 @@ static int cmos_nvram_write(void *priv,
}
spin_unlock_irq(&rtc_lock);
- return retval;
+ return count ? -EIO : 0;
}
/*----------------------------------------------------------------*/
Patches currently in stable-queue which might be from joychakr@xxxxxxxxxx are
queue-4.19/rtc-cmos-fix-return-value-of-nvmem-callbacks.patch
