[PATCH] spi: cadence-quadspi: Fix build warning on 32-bit platforms

[PATCH] spi: cadence-quadspi: Fix build warning on 32-bit platforms

[Pratyush Yadav]

The kernel test robot reports the following warning.

drivers/spi/spi-cadence-quadspi.c:966:24: warning: comparison of distinct pointer types ('typeof (len) *' (aka 'unsigned int *') and 'typeof (500UL) *' (aka 'unsigned long *')) [-Wcompare-distinct-pointer-types]
                                            msecs_to_jiffies(max(len, 500UL)))) {
                                                             ^~~~~~~~~~~~~~~
   include/linux/minmax.h:58:19: note: expanded from macro 'max'
   #define max(x, y)       __careful_cmp(x, y, >)
                           ^~~~~~~~~~~~~~~~~~~~~~
   include/linux/minmax.h:42:24: note: expanded from macro '__careful_cmp'
           __builtin_choose_expr(__safe_cmp(x, y), \
                                 ^~~~~~~~~~~~~~~~
   include/linux/minmax.h:32:4: note: expanded from macro '__safe_cmp'
                   (__typecheck(x, y) && __no_side_effects(x, y))
                    ^~~~~~~~~~~~~~~~~
   include/linux/minmax.h:18:28: note: expanded from macro '__typecheck'
           (!!(sizeof((typeof(x) *)1 == (typeof(y) *)1)))
                      ~~~~~~~~~~~~~~ ^  ~~~~~~~~~~~~~~
   1 warning generated.

This happens because size_t is unsigned long on 64-bit platforms like
arm64 but it is unsigned int on 32-bit platforms like arm. Omitting the
"UL" would result in a warning on 64-bit platforms. Squash it by type
casting the arguments to size_t using max_t(). This way builds on both
type of platforms can be satisfied. There is no chance of any truncation
since 500 is small enough to fit into both int and long.

Fixes: f453f293979f ("spi: cadence-quadspi: Wait at least 500 ms for direct reads")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Pratyush Yadav <p.yadav@ti.com>
---
 drivers/spi/spi-cadence-quadspi.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/spi/spi-cadence-quadspi.c b/drivers/spi/spi-cadence-quadspi.c
index 06a65e9a8a60..af13c0025bf5 100644
--- a/drivers/spi/spi-cadence-quadspi.c
+++ b/drivers/spi/spi-cadence-quadspi.c
@@ -1150,7 +1150,7 @@ static int cqspi_direct_read_execute(struct cqspi_flash_pdata *f_pdata,

 	dma_async_issue_pending(cqspi->rx_chan);
 	if (!wait_for_completion_timeout(&cqspi->rx_dma_complete,
-					 msecs_to_jiffies(max(len, 500UL)))) {
+					 msecs_to_jiffies(max_t(size_t, len, 500)))) {
 		dmaengine_terminate_sync(cqspi->rx_chan);
 		dev_err(dev, "DMA wait_for_completion_timeout\n");
 		ret = -ETIMEDOUT;
--
2.28.0

Re: [PATCH] spi: cadence-quadspi: Fix build warning on 32-bit platforms

[Mark Brown]

On Fri, 8 Jan 2021 23:44:57 +0530, Pratyush Yadav wrote:
> The kernel test robot reports the following warning.
> 
> drivers/spi/spi-cadence-quadspi.c:966:24: warning: comparison of distinct pointer types ('typeof (len) *' (aka 'unsigned int *') and 'typeof (500UL) *' (aka 'unsigned long *')) [-Wcompare-distinct-pointer-types]
>                                             msecs_to_jiffies(max(len, 500UL)))) {
>                                                              ^~~~~~~~~~~~~~~
>    include/linux/minmax.h:58:19: note: expanded from macro 'max'
>    #define max(x, y)       __careful_cmp(x, y, >)
>                            ^~~~~~~~~~~~~~~~~~~~~~
>    include/linux/minmax.h:42:24: note: expanded from macro '__careful_cmp'
>            __builtin_choose_expr(__safe_cmp(x, y), \
>                                  ^~~~~~~~~~~~~~~~
>    include/linux/minmax.h:32:4: note: expanded from macro '__safe_cmp'
>                    (__typecheck(x, y) && __no_side_effects(x, y))
>                     ^~~~~~~~~~~~~~~~~
>    include/linux/minmax.h:18:28: note: expanded from macro '__typecheck'
>            (!!(sizeof((typeof(x) *)1 == (typeof(y) *)1)))
>                       ~~~~~~~~~~~~~~ ^  ~~~~~~~~~~~~~~
>    1 warning generated.
> 
> [...]

Applied to

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git for-next

Thanks!

[1/1] spi: cadence-quadspi: Fix build warning on 32-bit platforms
      commit: 2ef0170e90391f1adb31c449059b8efdc923707c

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark