* [PATCH v2] drivers: net: xgene: Rewrite loop in xgene_enet_ecc_init()
@ 2014-10-22 7:39 Geert Uytterhoeven
2014-10-22 19:34 ` David Miller
0 siblings, 1 reply; 6+ messages in thread
From: Geert Uytterhoeven @ 2014-10-22 7:39 UTC (permalink / raw)
To: David S. Miller, Iyappan Subramanian, Keyur Chudgar
Cc: netdev, linux-kernel, Geert Uytterhoeven
drivers/net/ethernet/apm/xgene/xgene_enet_sgmac.c: In function ‘xgene_enet_ecc_init’:
drivers/net/ethernet/apm/xgene/xgene_enet_sgmac.c:126: warning: ‘data’ may be used uninitialized in this function
Depending on the arbitrary value on the stack, the loop may terminate
too early, and cause a bogus -ENODEV failure.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
---
v2: Rewrite the loop instead of pre-initializing data.
drivers/net/ethernet/apm/xgene/xgene_enet_sgmac.c | 12 +++++-------
1 file changed, 5 insertions(+), 7 deletions(-)
diff --git a/drivers/net/ethernet/apm/xgene/xgene_enet_sgmac.c b/drivers/net/ethernet/apm/xgene/xgene_enet_sgmac.c
index e6d24c2101982444..2a497b38ed420495 100644
--- a/drivers/net/ethernet/apm/xgene/xgene_enet_sgmac.c
+++ b/drivers/net/ethernet/apm/xgene/xgene_enet_sgmac.c
@@ -127,17 +127,15 @@ static int xgene_enet_ecc_init(struct xgene_enet_pdata *p)
int i;
xgene_enet_wr_diag_csr(p, ENET_CFG_MEM_RAM_SHUTDOWN_ADDR, 0);
- for (i = 0; i < 10 && data != ~0U ; i++) {
+ for (i = 0; i < 10; i++) {
usleep_range(100, 110);
data = xgene_enet_rd_diag_csr(p, ENET_BLOCK_MEM_RDY_ADDR);
+ if (data == ~0U)
+ return 0;
}
- if (data != ~0U) {
- netdev_err(ndev, "Failed to release memory from shutdown\n");
- return -ENODEV;
- }
-
- return 0;
+ netdev_err(ndev, "Failed to release memory from shutdown\n");
+ return -ENODEV;
}
static void xgene_enet_config_ring_if_assoc(struct xgene_enet_pdata *p)
--
1.9.1
^ permalink raw reply related [flat|nested] 6+ messages in thread* Re: [PATCH v2] drivers: net: xgene: Rewrite loop in xgene_enet_ecc_init()
2014-10-22 7:39 [PATCH v2] drivers: net: xgene: Rewrite loop in xgene_enet_ecc_init() Geert Uytterhoeven
@ 2014-10-22 19:34 ` David Miller
2014-10-22 19:50 ` Geert Uytterhoeven
0 siblings, 1 reply; 6+ messages in thread
From: David Miller @ 2014-10-22 19:34 UTC (permalink / raw)
To: geert; +Cc: isubramanian, kchudgar, netdev, linux-kernel
From: Geert Uytterhoeven <geert@linux-m68k.org>
Date: Wed, 22 Oct 2014 09:39:41 +0200
> drivers/net/ethernet/apm/xgene/xgene_enet_sgmac.c: In function ‘xgene_enet_ecc_init’:
> drivers/net/ethernet/apm/xgene/xgene_enet_sgmac.c:126: warning: ‘data’ may be used uninitialized in this function
>
> Depending on the arbitrary value on the stack, the loop may terminate
> too early, and cause a bogus -ENODEV failure.
>
> Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
> ---
> v2: Rewrite the loop instead of pre-initializing data.
I hate to be a pest, but like the other patch of your's I think
a do { } while() works best here because the intent is clearly
to run the loop at least once, right?
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH v2] drivers: net: xgene: Rewrite loop in xgene_enet_ecc_init()
2014-10-22 19:34 ` David Miller
@ 2014-10-22 19:50 ` Geert Uytterhoeven
2014-10-22 20:12 ` David Miller
0 siblings, 1 reply; 6+ messages in thread
From: Geert Uytterhoeven @ 2014-10-22 19:50 UTC (permalink / raw)
To: David Miller
Cc: isubramanian, kchudgar, netdev@vger.kernel.org,
linux-kernel@vger.kernel.org
On Wed, Oct 22, 2014 at 9:34 PM, David Miller <davem@davemloft.net> wrote:
> From: Geert Uytterhoeven <geert@linux-m68k.org>
> Date: Wed, 22 Oct 2014 09:39:41 +0200
>
>> drivers/net/ethernet/apm/xgene/xgene_enet_sgmac.c: In function ‘xgene_enet_ecc_init’:
>> drivers/net/ethernet/apm/xgene/xgene_enet_sgmac.c:126: warning: ‘data’ may be used uninitialized in this function
>>
>> Depending on the arbitrary value on the stack, the loop may terminate
>> too early, and cause a bogus -ENODEV failure.
>>
>> Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
>> ---
>> v2: Rewrite the loop instead of pre-initializing data.
>
> I hate to be a pest, but like the other patch of your's I think
> a do { } while() works best here because the intent is clearly
> to run the loop at least once, right?
I wanted to avoid checking for "data != ~0U" twice: once to abort the loop,
and once to check if a timeout happened.
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH v2] drivers: net: xgene: Rewrite loop in xgene_enet_ecc_init()
2014-10-22 19:50 ` Geert Uytterhoeven
@ 2014-10-22 20:12 ` David Miller
2014-10-23 7:05 ` Geert Uytterhoeven
2014-10-23 7:06 ` Geert Uytterhoeven
0 siblings, 2 replies; 6+ messages in thread
From: David Miller @ 2014-10-22 20:12 UTC (permalink / raw)
To: geert; +Cc: isubramanian, kchudgar, netdev, linux-kernel
From: Geert Uytterhoeven <geert@linux-m68k.org>
Date: Wed, 22 Oct 2014 21:50:06 +0200
> On Wed, Oct 22, 2014 at 9:34 PM, David Miller <davem@davemloft.net> wrote:
>> From: Geert Uytterhoeven <geert@linux-m68k.org>
>> Date: Wed, 22 Oct 2014 09:39:41 +0200
>>
>>> drivers/net/ethernet/apm/xgene/xgene_enet_sgmac.c: In function ‘xgene_enet_ecc_init’:
>>> drivers/net/ethernet/apm/xgene/xgene_enet_sgmac.c:126: warning: ‘data’ may be used uninitialized in this function
>>>
>>> Depending on the arbitrary value on the stack, the loop may terminate
>>> too early, and cause a bogus -ENODEV failure.
>>>
>>> Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
>>> ---
>>> v2: Rewrite the loop instead of pre-initializing data.
>>
>> I hate to be a pest, but like the other patch of your's I think
>> a do { } while() works best here because the intent is clearly
>> to run the loop at least once, right?
>
> I wanted to avoid checking for "data != ~0U" twice: once to abort the loop,
> and once to check if a timeout happened.
Hmmm:
do {
usleep_range(...);
data = ...();
if (data == ~0)
return 0;
} while (++i < 10);
netdev_err(...);
return -ENODEV;
Why would you have to check data twice?
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH v2] drivers: net: xgene: Rewrite loop in xgene_enet_ecc_init()
2014-10-22 20:12 ` David Miller
@ 2014-10-23 7:05 ` Geert Uytterhoeven
2014-10-23 7:06 ` Geert Uytterhoeven
1 sibling, 0 replies; 6+ messages in thread
From: Geert Uytterhoeven @ 2014-10-23 7:05 UTC (permalink / raw)
To: David Miller
Cc: Iyappan Subramanian, kchudgar, netdev@vger.kernel.org,
linux-kernel@vger.kernel.org
On Wed, Oct 22, 2014 at 10:12 PM, David Miller <davem@davemloft.net> wrote:
> From: Geert Uytterhoeven <geert@linux-m68k.org>
> Date: Wed, 22 Oct 2014 21:50:06 +0200
>
>> On Wed, Oct 22, 2014 at 9:34 PM, David Miller <davem@davemloft.net> wrote:
>>> From: Geert Uytterhoeven <geert@linux-m68k.org>
>>> Date: Wed, 22 Oct 2014 09:39:41 +0200
>>>
>>>> drivers/net/ethernet/apm/xgene/xgene_enet_sgmac.c: In function ‘xgene_enet_ecc_init’:
>>>> drivers/net/ethernet/apm/xgene/xgene_enet_sgmac.c:126: warning: ‘data’ may be used uninitialized in this function
>>>>
>>>> Depending on the arbitrary value on the stack, the loop may terminate
>>>> too early, and cause a bogus -ENODEV failure.
>>>>
>>>> Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
>>>> ---
>>>> v2: Rewrite the loop instead of pre-initializing data.
>>>
>>> I hate to be a pest, but like the other patch of your's I think
>>> a do { } while() works best here because the intent is clearly
>>> to run the loop at least once, right?
>>
>> I wanted to avoid checking for "data != ~0U" twice: once to abort the loop,
>> and once to check if a timeout happened.
>
> Hmmm:
>
> do {
> usleep_range(...);
> data = ...();
> if (data == ~0)
> return 0;
> } while (++i < 10);
>
> netdev_err(...);
> return -ENODEV;
>
> Why would you have to check data twice?
--
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH v2] drivers: net: xgene: Rewrite loop in xgene_enet_ecc_init()
2014-10-22 20:12 ` David Miller
2014-10-23 7:05 ` Geert Uytterhoeven
@ 2014-10-23 7:06 ` Geert Uytterhoeven
1 sibling, 0 replies; 6+ messages in thread
From: Geert Uytterhoeven @ 2014-10-23 7:06 UTC (permalink / raw)
To: David Miller
Cc: Iyappan Subramanian, kchudgar, netdev@vger.kernel.org,
linux-kernel@vger.kernel.org
On Wed, Oct 22, 2014 at 10:12 PM, David Miller <davem@davemloft.net> wrote:
> From: Geert Uytterhoeven <geert@linux-m68k.org>
> Date: Wed, 22 Oct 2014 21:50:06 +0200
>
>> On Wed, Oct 22, 2014 at 9:34 PM, David Miller <davem@davemloft.net> wrote:
>>> From: Geert Uytterhoeven <geert@linux-m68k.org>
>>> Date: Wed, 22 Oct 2014 09:39:41 +0200
>>>
>>>> drivers/net/ethernet/apm/xgene/xgene_enet_sgmac.c: In function ‘xgene_enet_ecc_init’:
>>>> drivers/net/ethernet/apm/xgene/xgene_enet_sgmac.c:126: warning: ‘data’ may be used uninitialized in this function
>>>>
>>>> Depending on the arbitrary value on the stack, the loop may terminate
>>>> too early, and cause a bogus -ENODEV failure.
>>>>
>>>> Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
>>>> ---
>>>> v2: Rewrite the loop instead of pre-initializing data.
>>>
>>> I hate to be a pest, but like the other patch of your's I think
>>> a do { } while() works best here because the intent is clearly
>>> to run the loop at least once, right?
>>
>> I wanted to avoid checking for "data != ~0U" twice: once to abort the loop,
>> and once to check if a timeout happened.
>
> Hmmm:
>
> do {
> usleep_range(...);
> data = ...();
> if (data == ~0)
> return 0;
> } while (++i < 10);
>
> netdev_err(...);
> return -ENODEV;
>
> Why would you have to check data twice?
Yes, that would work to.
Feel free to do s/for (i = 0; i < 10; i++)/do/ and s/}/} while (++i < 10);/
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
^ permalink raw reply [flat|nested] 6+ messages in thread
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2014-10-22 7:39 [PATCH v2] drivers: net: xgene: Rewrite loop in xgene_enet_ecc_init() Geert Uytterhoeven
2014-10-22 19:34 ` David Miller
2014-10-22 19:50 ` Geert Uytterhoeven
2014-10-22 20:12 ` David Miller
2014-10-23 7:05 ` Geert Uytterhoeven
2014-10-23 7:06 ` Geert Uytterhoeven
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