[Intel-gfx] [PATCH igt] lib: add igt_debugfs_read()

Paulo Zanoni przanoni at gmail.com
Tue Jul 21 11:01:21 PDT 2015


2015-07-21 14:43 GMT-03:00 Daniel Vetter <daniel at ffwll.ch>:
> On Tue, Jul 21, 2015 at 02:08:23PM -0300, Paulo Zanoni wrote:
>> From: Paulo Zanoni <paulo.r.zanoni at intel.com>
>>
>> A helpful function for when you want to read a whole debugfs file to a
>> string and don't want to worry about opening and closing file
>> descriptors and asserting buffer sizes.
>>
>> We've been using this already for kms_frontbuffer_tracking and
>> kms_fbcon_fbt, so the only test with new code here is kms_fbc_crc.
>>
>> Also notice that for kms_fbc_crc we had to increase the buffer size
>> since the file can sometimes be bigger than 64 bytes - depending on
>> the reason why FBC is disabled.
>>
>> Of course, there are probably many other programs we can patch, but
>> I'm not doing this now.
>>
>> Signed-off-by: Paulo Zanoni <paulo.r.zanoni at intel.com>
>> ---
>>  lib/igt_debugfs.c                | 27 +++++++++++++++++++++++++++
>>  lib/igt_debugfs.h                |  1 +
>>  tests/kms_fbc_crc.c              | 18 ++++--------------
>>  tests/kms_fbcon_fbt.c            | 25 ++++---------------------
>>  tests/kms_frontbuffer_tracking.c | 33 ++++++++-------------------------
>>  5 files changed, 44 insertions(+), 60 deletions(-)
>>
>> diff --git a/lib/igt_debugfs.c b/lib/igt_debugfs.c
>> index a2c6fe2..bc1bb05 100644
>> --- a/lib/igt_debugfs.c
>> +++ b/lib/igt_debugfs.c
>> @@ -185,6 +185,33 @@ FILE *igt_debugfs_fopen(const char *filename,
>>       return fopen(buf, mode);
>>  }
>>
>> +/**
>> + * igt_debugfs_read:
>> + * @filename: file name
>> + * @buf: buffer where the contents will be stored, allocated by the caller
>> + * @buf_size: size of the buffer
>> + *
>> + * This function opens the debugfs file, reads it, stores the content in the
>> + * provided buffer, then closes the file. Users should make sure that the buffer
>> + * provided is big enough to fit the whole file, plus one byte.
>
> Hm if we want a helper function to slurp in an entire file I'd go with one
> that mallocs a suitably big buffer. That means more free calls, but imo
> that's less onerous than getting buffer sizes right (well at least for a
> library function).

Since the files are usually very small, I'm not a big fan of the
malloc/free version. But maybe we could have both the malloc and the
non-malloc version in case we start having to deal with big debugfs
files.

>
> If you don't like that I'd rename this with a __ prefix and do a
>
> #define igt_debugfs_read(file, buf) \
>         __igt_debugfs_read((file), (buf), sizeof(buf))
>
> That way it's fairly impossible to get the static sizing wrong at least.

Good idea! I'll do this.

> -Daniel
>
>> + */
>> +void igt_debugfs_read(const char *filename, char *buf, int buf_size)
>> +{
>> +     FILE *file;
>> +     size_t n_read;
>> +
>> +     file = igt_debugfs_fopen(filename, "r");
>> +     igt_assert(file);
>> +
>> +     n_read = fread(buf, 1, buf_size - 1, file);
>> +     igt_assert(n_read > 0);
>> +     igt_assert(feof(file));
>> +
>> +     buf[n_read] = '\0';
>> +
>> +     igt_assert(fclose(file) == 0);
>> +}
>> +
>>  /*
>>   * Pipe CRC
>>   */
>> diff --git a/lib/igt_debugfs.h b/lib/igt_debugfs.h
>> index ece7148..a0bb75e 100644
>> --- a/lib/igt_debugfs.h
>> +++ b/lib/igt_debugfs.h
>> @@ -34,6 +34,7 @@ enum pipe;
>>  int igt_debugfs_open(const char *filename, int mode);
>>  FILE *igt_debugfs_fopen(const char *filename,
>>                       const char *mode);
>> +void igt_debugfs_read(const char *filename, char *buf, int buf_size);
>>
>>  /*
>>   * Pipe CRC
>> diff --git a/tests/kms_fbc_crc.c b/tests/kms_fbc_crc.c
>> index f2a86a6..28cc165 100644
>> --- a/tests/kms_fbc_crc.c
>> +++ b/tests/kms_fbc_crc.c
>> @@ -215,14 +215,9 @@ static void fill_mmap_gtt(data_t *data, uint32_t handle, unsigned char color)
>>
>>  static bool fbc_enabled(data_t *data)
>>  {
>> -     FILE *status;
>> -     char str[64] = {};
>> +     char str[128] = {};
>>
>> -     status = igt_debugfs_fopen("i915_fbc_status", "r");
>> -     igt_assert(status);
>> -
>> -     igt_assert(fread(str, 1, sizeof(str) - 1, status) > 0);
>> -     fclose(status);
>> +     igt_debugfs_read("i915_fbc_status", str, sizeof(str));
>>       return strstr(str, "FBC enabled") != NULL;
>>  }
>>
>> @@ -544,8 +539,7 @@ igt_main
>>       igt_skip_on_simulation();
>>
>>       igt_fixture {
>> -             char buf[64];
>> -             FILE *status;
>> +             char buf[128];
>>
>>               data.drm_fd = drm_open_any_master();
>>               kmstest_set_vt_graphics_mode();
>> @@ -554,11 +548,7 @@ igt_main
>>
>>               igt_require_pipe_crc();
>>
>> -             status = igt_debugfs_fopen("i915_fbc_status", "r");
>> -             igt_require_f(status, "No i915_fbc_status found\n");
>> -             igt_assert_lt(0, fread(buf, 1, sizeof(buf), status));
>> -             fclose(status);
>> -             buf[sizeof(buf) - 1] = '\0';
>> +             igt_debugfs_read("i915_fbc_status", buf, sizeof(buf));
>>               igt_require_f(!strstr(buf, "unsupported on this chipset"),
>>                             "FBC not supported\n");
>>
>> diff --git a/tests/kms_fbcon_fbt.c b/tests/kms_fbcon_fbt.c
>> index f075014..c201fde 100644
>> --- a/tests/kms_fbcon_fbt.c
>> +++ b/tests/kms_fbcon_fbt.c
>> @@ -86,28 +86,11 @@ static void teardown_drm(struct drm_info *drm)
>>       igt_assert(close(drm->fd) == 0);
>>  }
>>
>> -static void debugfs_read(const char *filename, char *buf, int buf_size)
>> -{
>> -     FILE *file;
>> -     size_t n_read;
>> -
>> -     file = igt_debugfs_fopen(filename, "r");
>> -     igt_assert(file);
>> -
>> -     n_read = fread(buf, 1, buf_size - 1, file);
>> -     igt_assert(n_read > 0);
>> -     igt_assert(feof(file));
>> -
>> -     buf[n_read] = '\0';
>> -
>> -     igt_assert(fclose(file) == 0);
>> -}
>> -
>>  static bool fbc_supported_on_chipset(void)
>>  {
>>       char buf[128];
>>
>> -     debugfs_read("i915_fbc_status", buf, ARRAY_SIZE(buf));
>> +     igt_debugfs_read("i915_fbc_status", buf, ARRAY_SIZE(buf));
>>       return !strstr(buf, "FBC unsupported on this chipset\n");
>>  }
>>
>> @@ -120,7 +103,7 @@ static bool fbc_is_enabled(void)
>>  {
>>       char buf[128];
>>
>> -     debugfs_read("i915_fbc_status", buf, ARRAY_SIZE(buf));
>> +     igt_debugfs_read("i915_fbc_status", buf, ARRAY_SIZE(buf));
>>       return strstr(buf, "FBC enabled\n");
>>  }
>>
>> @@ -172,7 +155,7 @@ static bool psr_supported_on_chipset(void)
>>  {
>>       char buf[256];
>>
>> -     debugfs_read("i915_edp_psr_status", buf, ARRAY_SIZE(buf));
>> +     igt_debugfs_read("i915_edp_psr_status", buf, ARRAY_SIZE(buf));
>>       return strstr(buf, "Sink_Support: yes\n");
>>  }
>>
>> @@ -185,7 +168,7 @@ static bool psr_is_enabled(void)
>>  {
>>       char buf[256];
>>
>> -     debugfs_read("i915_edp_psr_status", buf, ARRAY_SIZE(buf));
>> +     igt_debugfs_read("i915_edp_psr_status", buf, ARRAY_SIZE(buf));
>>       return strstr(buf, "\nActive: yes\n");
>>  }
>>
>> diff --git a/tests/kms_frontbuffer_tracking.c b/tests/kms_frontbuffer_tracking.c
>> index e9be045..e162e91 100644
>> --- a/tests/kms_frontbuffer_tracking.c
>> +++ b/tests/kms_frontbuffer_tracking.c
>> @@ -556,28 +556,11 @@ static bool set_mode_for_params(struct modeset_params *params)
>>       return (rc == 0);
>>  }
>>
>> -static void debugfs_read(const char *filename, char *buf, int buf_size)
>> -{
>> -     FILE *file;
>> -     size_t n_read;
>> -
>> -     file = igt_debugfs_fopen(filename, "r");
>> -     igt_assert(file);
>> -
>> -     n_read = fread(buf, 1, buf_size - 1, file);
>> -     igt_assert(n_read > 0);
>> -     igt_assert(feof(file));
>> -
>> -     buf[n_read] = '\0';
>> -
>> -     igt_assert(fclose(file) == 0);
>> -}
>> -
>>  static bool fbc_is_enabled(void)
>>  {
>>       char buf[128];
>>
>> -     debugfs_read("i915_fbc_status", buf, ARRAY_SIZE(buf));
>> +     igt_debugfs_read("i915_fbc_status", buf, ARRAY_SIZE(buf));
>>       return strstr(buf, "FBC enabled\n");
>>  }
>>
>> @@ -585,7 +568,7 @@ static bool psr_is_enabled(void)
>>  {
>>       char buf[256];
>>
>> -     debugfs_read("i915_edp_psr_status", buf, ARRAY_SIZE(buf));
>> +     igt_debugfs_read("i915_edp_psr_status", buf, ARRAY_SIZE(buf));
>>       return (strstr(buf, "\nActive: yes\n"));
>>  }
>>
>> @@ -596,7 +579,7 @@ static struct timespec fbc_get_last_action(void)
>>       char *action;
>>       ssize_t n_read;
>>
>> -     debugfs_read("i915_fbc_status", buf, ARRAY_SIZE(buf));
>> +     igt_debugfs_read("i915_fbc_status", buf, ARRAY_SIZE(buf));
>>
>>       action = strstr(buf, "\nLast action:");
>>       igt_assert(action);
>> @@ -645,7 +628,7 @@ static void fbc_setup_last_action(void)
>>       char buf[128];
>>       char *action;
>>
>> -     debugfs_read("i915_fbc_status", buf, ARRAY_SIZE(buf));
>> +     igt_debugfs_read("i915_fbc_status", buf, ARRAY_SIZE(buf));
>>
>>       action = strstr(buf, "\nLast action:");
>>       if (!action) {
>> @@ -664,7 +647,7 @@ static bool fbc_is_compressing(void)
>>  {
>>       char buf[128];
>>
>> -     debugfs_read("i915_fbc_status", buf, ARRAY_SIZE(buf));
>> +     igt_debugfs_read("i915_fbc_status", buf, ARRAY_SIZE(buf));
>>       return strstr(buf, "\nCompressing: yes\n") != NULL;
>>  }
>>
>> @@ -677,7 +660,7 @@ static void fbc_setup_compressing(void)
>>  {
>>       char buf[128];
>>
>> -     debugfs_read("i915_fbc_status", buf, ARRAY_SIZE(buf));
>> +     igt_debugfs_read("i915_fbc_status", buf, ARRAY_SIZE(buf));
>>
>>       if (strstr(buf, "\nCompressing:"))
>>               fbc.supports_compressing = true;
>> @@ -1187,7 +1170,7 @@ static bool fbc_supported_on_chipset(void)
>>  {
>>       char buf[128];
>>
>> -     debugfs_read("i915_fbc_status", buf, ARRAY_SIZE(buf));
>> +     igt_debugfs_read("i915_fbc_status", buf, ARRAY_SIZE(buf));
>>       return !strstr(buf, "FBC unsupported on this chipset\n");
>>  }
>>
>> @@ -1211,7 +1194,7 @@ static bool psr_sink_has_support(void)
>>  {
>>       char buf[256];
>>
>> -     debugfs_read("i915_edp_psr_status", buf, ARRAY_SIZE(buf));
>> +     igt_debugfs_read("i915_edp_psr_status", buf, ARRAY_SIZE(buf));
>>       return strstr(buf, "Sink_Support: yes\n");
>>  }
>>
>> --
>> 2.1.4
>>
>> _______________________________________________
>> Intel-gfx mailing list
>> Intel-gfx at lists.freedesktop.org
>> http://lists.freedesktop.org/mailman/listinfo/intel-gfx
>
> --
> Daniel Vetter
> Software Engineer, Intel Corporation
> http://blog.ffwll.ch



-- 
Paulo Zanoni


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