Greetings,
(this goes mostly to David, I assume)
In at24_ee_write:
> + /* Writes fail if the previous one didn't complete yet. We'll
> + * loop a few times until this one succeeds, waiting at least
> + * long enough for one entire page write to work.
> + */
> + timeout = jiffies + msecs_to_jiffies(AT24_EE_TIMEOUT);
> + for (retries = 0; retries < 3; retries++) {
> +
> + if (at24->use_smbus) {
> + status = i2c_smbus_write_i2c_block_data(client,
> + offset, count, buf);
> + if (status == 0)
> + status = count;
> + } else {
> + status = i2c_transfer(client->adapter, &msg, 1);
> + if (status == 1)
> + status = count;
> + }
> + dev_dbg(&client->dev, "write [EMAIL PROTECTED] --> %zd (%ld)\n",
> + count, offset, status, jiffies);
> +
> + if (status == count)
> + return count;
> +
> + if (retries < 3 || time_after(timeout, jiffies)) {
> + /* REVISIT: at HZ=100, this is sloooow */
> + msleep(1);
> + continue;
> + }
> + }
I assume 'retries < 3' (always true) and 'continue' (nothing follows)
are left-overs from earlier revisions and can be thrown out? My main
questions is 'msleep(1)' though: As I understand it, this means the
for-loop will wait roughly 3ms on failures until it reports a timeout
(assuming good precision of msleep). Comparing this to AT24_EE_TIMEOUT
(25 ms), it looks to me that the msleep value could be increased a
little (maybe to AT24_EE_TIMEOUT / 3)? Or is i2c_transfer slow enough
and can we count on that behaviour?
All the best,
Wolfram
--
Dipl.-Ing. Wolfram Sang | http://www.pengutronix.de
Pengutronix - Linux Solutions for Science and Industry
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