| Message ID | 20240612083635.1253039-1-joychakr@google.com |
|---|---|
| State | New |
| Headers | show |
| Series | rtc: cmos: Fix return value of nvmem callbacks | expand |
On Wed, Jun 12, 2024 at 08:36:35AM +0000, Joy Chakraborty wrote: > 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@vger.kernel.org > Signed-off-by: Joy Chakraborty <joychakr@google.com> > --- Thanks! Reviewed-by: Dan Carpenter <dan.carpenter@linaro.org> After we fix all the these, can we add a warning once message to detect when people introduce new bugs? It could either go into __nvmem_reg_read/write() or bin_attr_nvmem_read/write(). I think bin_attr_nvmem_read() is the only caller where the buggy functions work but that's the caller that most people use I guess. regards, dan carpenter
On Wed, Jun 12, 2024 at 2:53 PM Dan Carpenter <dan.carpenter@linaro.org> wrote: > > On Wed, Jun 12, 2024 at 08:36:35AM +0000, Joy Chakraborty wrote: > > 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@vger.kernel.org > > Signed-off-by: Joy Chakraborty <joychakr@google.com> > > --- > > Thanks! > > Reviewed-by: Dan Carpenter <dan.carpenter@linaro.org> > > After we fix all the these, can we add a warning once message to detect > when people introduce new bugs? It could either go into > __nvmem_reg_read/write() or bin_attr_nvmem_read/write(). I think > bin_attr_nvmem_read() is the only caller where the buggy functions work > but that's the caller that most people use I guess. > Sure I can do that. Yes, I think most users use this via sysfs using bin_attr_nvmem_read() hence it works. Thanks Joy > regards, > dan carpenter >
diff --git a/drivers/rtc/rtc-cmos.c b/drivers/rtc/rtc-cmos.c index 7d99cd2c37a0..35dca2accbb8 100644 --- a/drivers/rtc/rtc-cmos.c +++ b/drivers/rtc/rtc-cmos.c @@ -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; } /*----------------------------------------------------------------*/
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@vger.kernel.org Signed-off-by: Joy Chakraborty <joychakr@google.com> --- drivers/rtc/rtc-cmos.c | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-)