Re: [PATCH v11 3/4] i2c: aspeed: added driver for Aspeed I2C

Brendan Higgins
2017-06-27T08:29:12Z

On Fri, Jun 23, 2017 at 11:43 AM, Wolfram Sang <wsa@the-dreams.de> wrote:
> On Tue, Jun 20, 2017 at 02:15:15PM -0700, Brendan Higgins wrote:
>> Added initial master support for Aspeed I2C controller. Supports
>> fourteen busses present in AST24XX and AST25XX BMC SoCs by Aspeed.
>>
>> Signed-off-by: Brendan Higgins <brendanhiggins@google.com>
>
> Applied to for-next, thanks for all the hard work!

Thanks for the patience!

>
> One question however which can be solved incrementally if needed:
>
>> + if (command & ASPEED_I2CD_SDA_LINE_STS) {
>> + /* Bus is idle: no recovery needed. */
>> + if (command & ASPEED_I2CD_SCL_LINE_STS)
>> + goto out;
>> + dev_dbg(bus->dev, "SCL hung (state %x), attempting recovery\n",
>> + command);
>> +
>> + reinit_completion(&bus->cmd_complete);
>> + writel(ASPEED_I2CD_M_STOP_CMD, bus->base + ASPEED_I2C_CMD_REG);
>
> If SCL is stuck low, how do you want to send a STOP?
>

Fair point. I should probably drop that in the future and just do a
reset, and even then, doing a
reset is probably just wishful thinking. If a slave is holding down
SCL, we are pretty screwed.