Hi Dan,
On 22.02.2018 09:37, Dan Carpenter wrote:
> On Wed, Feb 21, 2018 at 09:42:10PM +0530, Ajay Singh wrote:
>> Use existing macro GENMASK to get the bitmask value. Moved the code to
>> get the bitmask value outside the loop, as its only required one time.
>>
>> Signed-off-by: Ajay Singh <[email protected]>
>> ---
>> drivers/staging/wilc1000/wilc_spi.c | 3 +--
>> 1 file changed, 1 insertion(+), 2 deletions(-)
>>
>> diff --git a/drivers/staging/wilc1000/wilc_spi.c
>> b/drivers/staging/wilc1000/wilc_spi.c
>> index 131d2b7..c63f534 100644
>> --- a/drivers/staging/wilc1000/wilc_spi.c
>> +++ b/drivers/staging/wilc1000/wilc_spi.c
>> @@ -955,6 +955,7 @@ static int wilc_spi_read_int(struct wilc *wilc, u32
>> *int_status)
>> tmp = (byte_cnt >> 2) & IRQ_DMA_WD_CNT_MASK;
>>
>> j = 0;
>> + unknown_mask = GENMASK(g_spi.nint - 1, 0);
>> do {
>> wilc_spi_read_reg(wilc, 0x1a90, &irq_flags);
>> tmp |= ((irq_flags >> 27) << IRG_FLAGS_OFFSET);
>> @@ -964,8 +965,6 @@ static int wilc_spi_read_int(struct wilc *wilc, u32
>> *int_status)
>> tmp |= (((irq_flags >> 0) & 0x7) << k);
>> }
>>
>> - unknown_mask = ~((1ul << g_spi.nint) - 1);
>> -
>
> This isn't right at all... Say g_spi.nint is zero, then we're doing
> GENMASK(-1, 0) which seems like it should be undefined. If g_spi.nint
> is 1 then "GENMASK(1 - 1, 0)" is 0x1 but "~((1 < 1) - 1)" is ~0x1.
>
Even in this driver g_spi.nint is always constant and equal with NUM_INT_EXT
(which is 3), it seems that enabling interrupts before initializing g_spi.nint
may lead to the state where g_spi.nint = 0, as Dan pointed.
int wilc1000_wlan_init(struct net_device *dev, struct wilc_vif *vif)
{
// ...
if (wl->gpio >= 0 && init_irq(dev)) {
ret = -EIO;
goto _fail_locks_;
}
// ...
ret = linux_wlan_start_firmware(dev); -> calls
linux_wlan_start_firmware which in turn calls wilc->hif_func->hif_sync_ext(wilc,
NUM_INT_EXT);
}
Thank you,
Claudiu Beznea
> I'm done reviewing this patch series... You need to be more careful.
> Create a small test program to test your patches. As a reviewer,
> creating test programs is how I review your patches.
>
> #include <sys/types.h>
> #include <sys/stat.h>
> #include <fcntl.h>
> #include <stdio.h>
> #include <stdlib.h>
> #include <limits.h>
> #include <string.h>
> #include "/home/dcarpenter/progs/smatch/devel/check_debug.h"
> #include "kernel.h"
> #include <assert.h>
> #include <fcntl.h>
> #include <sys/time.h>
> #include <sys/ioctl.h>
> #include <linux/blktrace_api.h>
> #include <linux/fs.h>
>
> #define BITS_PER_LONG 64
> #define GENMASK(h, l) \
> (((~0UL) - (1UL << (l)) + 1) & (~0UL >> (BITS_PER_LONG - 1 - (h))))
>
> int main(void)
> {
> int i;
> u32 mask1, mask2;
>
> for (i = 0; i < 32; i++) {
> mask1 = ~((1ul << i) - 1);
> mask2 = GENMASK(i - 1, 0);
> if (mask1 == mask2)
> continue;
> printf("ONE 0x%x %d\n", mask1, i);
> printf("TWO 0x%x\n", mask2);
> }
> return 0;
> }
>
> regards,
> dan carpenter
>
>
>
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>
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