[PATCH v7 21/21] OMAP2+: UART: Do not gate uart clocks if used for debug_prints

Govindraj govindraj.ti at gmail.com
Wed Oct 19 08:52:58 EDT 2011


On Wed, Oct 19, 2011 at 11:05 AM, Mohammed, Afzal <afzal at ti.com> wrote:
> Hi Govindraj,
>
> On Tue, Oct 18, 2011 at 21:05:41, R, Govindraj wrote:
>> If OMAP UART is used as console uart and debug is enabled,
>> avoid gating of uart clocks to print all debug prints.
> :
> :
>>                       console_uart_id = uart->num;
>>
>> +                     if (cmdline_find_option("debug")) {
>> +                             uart_debug = true;
>
> Shouldn't "loglevel" also be checked?
>

Might not be necessary,

loglevel only sets the option in console driver how a printk should be handled
from vprintk so any printk should be to sent to console or to syslogd action
where it will be buffered to a file(var/log/messages).

Any print's with any log level should be handled and printed to console.

consider below path below path

uart->ops
 -> runtime_get_sync
      -> omap_device_enable
          -> clock_enable

All the prints in given path are dev_dbgs for which we need debug to be set from
command line argument.

As stated in change log any dev_dbg prints from these path can be
redirect to uart->ops
so even before our clock was enabled we got redirected back to uart code.

So for dev_dbg prints from above path we need debug to be set from command-line
and we can prevent uart clock gating to this scenario.

--
Govindraj.R



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