| Message ID | 2423840.pM7qIRtGlE@wuerfel (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 06/03/2013 07:24 AM, Arnd Bergmann wrote: > 24778be20 "spi: convert drivers to use bits_per_word_mask" > removed the "default" statement in the spi_sirfsoc_setup_transfer > switch, causing a new warning: > > drivers/spi/spi-sirf.c: In function 'spi_sirfsoc_setup_transfer': > arch/arm/include/asm/io.h:90:2: warning: 'rxfifo_ctrl' may be used uninitialized in this function [-Wmaybe-uninitialized] > asm volatile("str %1, %0" > ^ > drivers/spi/spi-sirf.c:364:19: note: 'rxfifo_ctrl' was declared here > u32 txfifo_ctrl, rxfifo_ctrl; > ^ > > The compiler has correctly identified that this case may happen, > but since we know that things are horribly broken if bits_per_word > is ever something other than the values we tested, calling BUG() > is an appropriate action and tells the compiler that execution > will not continue afterwards. I guess this is fine, although BUG() seems a little scary, even though it is a bug. In some of the other drivers, I converted: if () { } else if () { } else { error } ... to: if () { } else { } ... the equivalent of which would be to just add a "default:" to, say, the 8-bpw case in the switch. But I guess I don't feel too strongly either way.
diff --git a/drivers/spi/spi-sirf.c b/drivers/spi/spi-sirf.c index 265a5c6..fc20bcf 100644 --- a/drivers/spi/spi-sirf.c +++ b/drivers/spi/spi-sirf.c @@ -409,6 +409,8 @@ spi_sirfsoc_setup_transfer(struct spi_device *spi, struct spi_transfer *t) rxfifo_ctrl = SIRFSOC_SPI_FIFO_THD(SIRFSOC_SPI_FIFO_SIZE / 2) | SIRFSOC_SPI_FIFO_WIDTH_DWORD; break; + default: + BUG(); } if (!(spi->mode & SPI_CS_HIGH))
24778be20 "spi: convert drivers to use bits_per_word_mask" removed the "default" statement in the spi_sirfsoc_setup_transfer switch, causing a new warning: drivers/spi/spi-sirf.c: In function 'spi_sirfsoc_setup_transfer': arch/arm/include/asm/io.h:90:2: warning: 'rxfifo_ctrl' may be used uninitialized in this function [-Wmaybe-uninitialized] asm volatile("str %1, %0" ^ drivers/spi/spi-sirf.c:364:19: note: 'rxfifo_ctrl' was declared here u32 txfifo_ctrl, rxfifo_ctrl; ^ The compiler has correctly identified that this case may happen, but since we know that things are horribly broken if bits_per_word is ever something other than the values we tested, calling BUG() is an appropriate action and tells the compiler that execution will not continue afterwards. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Stephen Warren <swarren@wwwdotorg.org> Cc: Mark Brown <broonie@kernel.org> --- I keep using the wrong address for Mark even though I know it doesn't work any more. Sorry for the duplicate mail.