From: Ian Abbott <abbotti@mev.co.uk>
To: Dan Carpenter <dan.carpenter@oracle.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-staging@lists.linux.dev,
H Hartley Sweeten <hsweeten@visionengravers.com>,
"Spencer E . Olson" <olsonse@umich.edu>
Subject: Re: [PATCH 0/5] staging: comedi: tests: Fix various issues
Date: Wed, 14 Apr 2021 13:34:23 +0100 [thread overview]
Message-ID: <2955bb05-fa59-c35a-b5a2-a5aedb4c96a8@mev.co.uk> (raw)
In-Reply-To: <20210414100905.GD6048@kadam>
On 14/04/2021 11:09, Dan Carpenter wrote:
> The test_ni_get_reg_value() function calls
> unittest(ni_get_reg_value_roffs(-1, O(0), T, 1) == -1,
> "check bad direct trigger arg for first reg->dest w/offs\n");
> The -1 is type promoted to a high positive value so src is greater than
> NI_NAMES_BASE. It's not clear that that was intentional.
> drivers/staging/comedi/drivers/tests/../ni_routes.h:269 ni_get_reg_value_roffs() warn: 'src' possible negative type promoted to high
I agree that it appears that ni_get_reg_value_roffs() will be returning
-1 as expected, but for the wrong reason. I think the intention was for
ni_get_reg_value_roffs() to call route_register_is_valid() with src=0 in
this case, but it actually calls ni_route_to_register() with src=-1
(because -1 gets converted to 0xffffffff in the test `if (src <
NI_NAMES_BASE)` where NI_NAMES_BASE is defined as 0x8000u).
>
> drivers/staging/comedi/drivers/ni_routes.c:61 ni_find_route_values() warn: 'device_family' sometimes too small '8,11' size = 30
> 59 for (i = 0; ni_all_route_values[i]; ++i) {
> 60 if (memcmp(ni_all_route_values[i]->family, device_family,
> ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> 61 strnlen(device_family, 30)) == 0) {
> ^^^^^^^^^^^^^^^^^^^^^^^^^^
> This whole memcmp() is very strange. Why not just use:
>
> if (strncmp(ni_all_route_values[i]->family, device_family, 30) == 0)
I think even a simple strcmp() would do as well because all the device
family strings and board name strings are null terminated. I don't know
why the magic number 30 is used here!
The above applies similarly to ni_find_valid_routes() too.
>
> 62 rv = &ni_all_route_values[i]->register_values[0][0];
> 63 break;
> 64 }
> 65 }
>
> There are a couple places where conditions could probably be deleted.
> drivers/staging/comedi/drivers/ni_mio_common.c:2363 ni_ai_cmd() warn: we tested 'dev->irq' before and it was 'true'
Agreed. In fact ni_ai_cmd() shouldn't be getting called at all if
dev->irq is 0.
> drivers/staging/comedi/drivers/usbdux.c:1192 usbduxsub_pwm_irq() warn: we tested 'devpriv->pwm_cmd_running' before and it was 'true'
Agreed.
> There is some commented out code that might be worth reviewing.
> drivers/staging/comedi/drivers/ni_mio_common.c:6306 ni_E_init() warn: odd binop '0x2 & 0x0'
Yes, that can be simplified.
> drivers/staging/comedi/drivers/cb_pcidas64.c:2229 use_hw_sample_counter() warn: ignoring unreachable code.
Yes, that is preceded by:
/* disable for now until I work out a race */
return 0;
But that change dates back to 2002. Perhaps we should use `#if 0`
`#endif` around the unreachable lines of code on the off-chance that it
gets revisited sometime!
> These places are using char for bitwise operations and there is some
> sign extension going on.
> drivers/staging/comedi/drivers/icp_multi.c:120 icp_multi_ai_insn_read() warn: using signed char for bitops
Agreed, range_code_analog[] ought to be unsigned char instead of plain char.
> drivers/staging/comedi/drivers/usbdux.c:1290 usbdux_pwm_pattern() warn: using signed char for bitops
> drivers/staging/comedi/drivers/usbdux.c:1292 usbdux_pwm_pattern() warn: using signed char for bitops
I think usbdux_pwm_pattern() should be using unsigned char throughout.
Also, the initialization `char sgn_mask = (16 << chan);` seems strange
because `chan` can be in the range 0 to 7 here!
--
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next prev parent reply other threads:[~2021-04-14 13:51 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-07 14:01 [PATCH 0/5] staging: comedi: tests: Fix various issues Ian Abbott
2021-04-07 14:01 ` [PATCH 1/5] staging: comedi: tests: ni_routes_test: Fix compilation error Ian Abbott
2021-04-07 14:01 ` [PATCH 2/5] staging: comedi: tests: ni_routes_test: Put complex values in parentheses Ian Abbott
2021-04-07 14:01 ` [PATCH 3/5] staging: comedi: tests: ni_routes_test: Avoid CamelCase: <RVi> Ian Abbott
2021-04-07 15:23 ` Spencer Olson
2021-04-07 14:01 ` [PATCH 4/5] staging: comedi: tests: ni_routes_test: Lines should not end with a '(' Ian Abbott
2021-04-07 14:01 ` [PATCH 5/5] staging: comedi: tests: Correct unittest_fptr Ian Abbott
2021-04-07 15:10 ` [PATCH 0/5] staging: comedi: tests: Fix various issues Greg Kroah-Hartman
2021-04-07 15:39 ` Ian Abbott
2021-04-07 15:48 ` Spencer Olson
2021-04-07 16:16 ` Ian Abbott
2021-04-07 17:26 ` Greg Kroah-Hartman
2021-04-07 18:20 ` Ian Abbott
2021-04-08 7:27 ` Greg Kroah-Hartman
2021-04-14 10:09 ` Dan Carpenter
2021-04-14 10:40 ` Ian Abbott
2021-04-14 12:34 ` Ian Abbott [this message]
2021-04-14 13:28 ` Dan Carpenter
2021-04-14 13:57 ` Spencer Olson
2021-04-14 17:24 ` Ian Abbott
2021-04-14 14:29 ` Spencer Olson
2021-04-14 17:05 ` Ian Abbott
2021-04-15 9:57 ` Ian Abbott
2021-04-14 12:40 ` Ian Abbott
2021-04-14 13:12 ` Greg Kroah-Hartman
2021-04-14 13:30 ` Dan Carpenter
2021-04-07 15:43 ` Spencer Olson
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