| Message ID | 1407387060-28992-1-git-send-email-xerofoiify@gmail.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 057f6061a1972b0d63383cbbbb98795e8ef0a752 |
| Headers | show |
On Thu, Aug 07, 2014 at 06:51:00AM +0200, Nick Krause wrote: > While compiling we see the following waring > > drivers/spi/spi-bfin5xx.c: In function 'bfin_spi_pump_transfers': > drivers/spi/spi-bfin5xx.c:695:6: warning: 'cr_width' may be used uninitialized > in this function [-Wuninitialized] > > Initialize it to prevent the above warning > > Signed-off-by: Nick Krause <xerofoify@gmail.com> > --- > drivers/spi/spi-bfin5xx.c | 3 +-- > 1 file changed, 1 insertion(+), 2 deletions(-) > > diff --git a/drivers/spi/spi-bfin5xx.c b/drivers/spi/spi-bfin5xx.c > index ebf720b..f268bf4 100644 > --- a/drivers/spi/spi-bfin5xx.c > +++ b/drivers/spi/spi-bfin5xx.c > @@ -559,7 +559,7 @@ static void bfin_spi_pump_transfers(unsigned long data) > struct spi_transfer *previous = NULL; > struct bfin_spi_slave_data *chip = NULL; > unsigned int bits_per_word; > - u16 cr, cr_width, dma_width, dma_config; > + u16 cr, cr_width = 0, dma_width, dma_config; > u32 tranf_success = 1; > u8 full_duplex = 0; > > @@ -648,7 +648,6 @@ static void bfin_spi_pump_transfers(unsigned long data) > } else if (bits_per_word == 8) { > drv_data->n_bytes = bits_per_word/8; > drv_data->len = transfer->len; > - cr_width = 0; > drv_data->ops = &bfin_bfin_spi_transfer_ops_u8; > } So if we ever hit that uninitialized case, where bits_per_word is neither 8 nor 16, we'll have ops set to NULL and end up wondering why the kernel crashes a bit further down in the code. Not really sure if that is an improvement. Guenter -- To unsubscribe from this list: send the line "unsubscribe linux-spi" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Wed, Aug 06, 2014 at 10:22:19PM -0700, Guenter Roeck wrote: > So if we ever hit that uninitialized case, where bits_per_word is > neither 8 nor 16, we'll have ops set to NULL and end up wondering > why the kernel crashes a bit further down in the code. Not really > sure if that is an improvement. It's not. The goal isn't to fix the warning, it's to fix the problem the compiler is telling you about - initialising to the wrong value is just as bad as not being initialised at all.
diff --git a/drivers/spi/spi-bfin5xx.c b/drivers/spi/spi-bfin5xx.c index ebf720b..f268bf4 100644 --- a/drivers/spi/spi-bfin5xx.c +++ b/drivers/spi/spi-bfin5xx.c @@ -559,7 +559,7 @@ static void bfin_spi_pump_transfers(unsigned long data) struct spi_transfer *previous = NULL; struct bfin_spi_slave_data *chip = NULL; unsigned int bits_per_word; - u16 cr, cr_width, dma_width, dma_config; + u16 cr, cr_width = 0, dma_width, dma_config; u32 tranf_success = 1; u8 full_duplex = 0; @@ -648,7 +648,6 @@ static void bfin_spi_pump_transfers(unsigned long data) } else if (bits_per_word == 8) { drv_data->n_bytes = bits_per_word/8; drv_data->len = transfer->len; - cr_width = 0; drv_data->ops = &bfin_bfin_spi_transfer_ops_u8; } cr = bfin_read(&drv_data->regs->ctl) & ~(BIT_CTL_TIMOD | BIT_CTL_WORDSIZE);
While compiling we see the following waring drivers/spi/spi-bfin5xx.c: In function 'bfin_spi_pump_transfers': drivers/spi/spi-bfin5xx.c:695:6: warning: 'cr_width' may be used uninitialized in this function [-Wuninitialized] Initialize it to prevent the above warning Signed-off-by: Nick Krause <xerofoify@gmail.com> --- drivers/spi/spi-bfin5xx.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)