Re: [PATCH] SPI: Fix distinct pointer types warning for ARCH=MIPS

[Nathan Chancellor <natechancellor@xxxxxxxxx>]

On Thu, Jan 07, 2021 at 07:57:04PM +0800, Yanteng Si wrote:
> Fix a new warning report by build for make ARCH=MIPS allmodconfig:
> 
> drivers/spi/spi-cadence-quadspi.c: In function 'cqspi_direct_read_execute':
>  ./include/linux/minmax.h:18:28: warning: comparison of distinct pointer types lacks a cast
>     18 |  (!!(sizeof((typeof(x) *)1 == (typeof(y) *)1)))
>        |                            ^~
>  ./include/linux/minmax.h:32:4: note: in expansion of macro '__typecheck'
>     32 |   (__typecheck(x, y) && __no_side_effects(x, y))
>        |    ^~~~~~~~~~~
>  ./include/linux/minmax.h:42:24: note: in expansion of macro '__safe_cmp'
>     42 |  __builtin_choose_expr(__safe_cmp(x, y), \
>        |                        ^~~~~~~~~~
>  ./include/linux/minmax.h:58:19: note: in expansion of macro '__careful_cmp'
>     58 | #define max(x, y) __careful_cmp(x, y, >)
>        |                   ^~~~~~~~~~~~~
>  drivers/spi/spi-cadence-quadspi.c:1153:24: note: in expansion of macro 'max'
>   1153 |       msecs_to_jiffies(max(len, 500UL)))) {
>        |                        ^~~
> 
> "len" is unsigned,however,"500" is unsigned long.
> 
> Signed-off-by: Yanteng Si <siyanteng@xxxxxxxxxxx>
> ---
>  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..576610ba1118 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(len, 500U)))) {
>  		dmaengine_terminate_sync(cqspi->rx_chan);
>  		dev_err(dev, "DMA wait_for_completion_timeout\n");
>  		ret = -ETIMEDOUT;
> -- 
> 2.27.0
> 

Isn't this just going to cause warnings on 64-bit platforms now because
size_t is defined as unsigned long and it will now be compared against
unsigned int? This fix should work for everyone, not sure how pretty it
is though.

Cheers,
Nathan

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;