Hi,
On Mon, Sep 16, 2013 at 10:20:54PM +0200, Ondrej Zary wrote:
> +static int snd_es938_read_reg(struct snd_es938 *chip, u8 reg, u8 *out)
> +{
> + u8 buf[8];
> + int i = 0, res;
> + u8 sysex[] = { MIDI_CMD_COMMON_SYSEX, 0x00, 0x00, ES938_ID,
> + ES938_CMD_REG_R, reg, MIDI_CMD_COMMON_SYSEX_END };
> + unsigned long end_time;
> +
> + snd_rawmidi_kernel_write(chip->rfile.output, sysex, sizeof(sysex));
> +
> + memset(buf, 0, sizeof(buf));
> + end_time = jiffies + msecs_to_jiffies(100);
> + while (i < sizeof(buf)) {
> + res = snd_rawmidi_kernel_read(chip->rfile.input, buf + i,
> + sizeof(buf) - i);
> + if (res > 0)
> + i += res;
> + if (time_after(jiffies, end_time))
> + return -1;
> + }
Forgive me, but I seem to faintly remember that it's preferred for
user code to tend towards non-jiffies-based timing (IIRC due to
NOHZ efforts etc.).
So if that actually is the case, then one might want to change it to
less jiffies-dependent handling (use non-jiffies helpers), but then how?
> +static void snd_es938_write_reg(struct snd_es938 *chip, u8 reg, u8 val)
> +{
> + u8 sysex[] = { MIDI_CMD_COMMON_SYSEX, 0x00, 0x00, ES938_ID,
> + ES938_CMD_REG_W, reg, val, MIDI_CMD_COMMON_SYSEX_END };
> +
> + snd_rawmidi_kernel_write(chip->rfile.output, sysex, sizeof(sysex));
snd_rawmidi_kernel_write() is prototyped as const unsigned char *buf,
so perhaps...
const unsigned char buf[] = ...;?
(static const probably not so useful
e.g. since static const may be rather prone to cache misses)
Though personally I do favour u8, since "char" seems so unsuitably stringy -
but the prototype currently doesn't offer it typed that way...
(Almost-)Reviewed-By: Andreas Mohr <and...@users.sf.net>
Andreas Mohr
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