[PATCH] drivers: Change calls to mdelay to msleep in order to stop CPU busy looping in mdfld_dsi_pkg_sender.c

[Nick Krause]

On Mon, Nov 17, 2014 at 3:40 AM, Jani Nikula
<jani.nikula at linux.intel.com> wrote:
> On Sat, 15 Nov 2014, Nicholas Krause <xerofoify at gmail.com> wrote:
>> Changes the calls of mdelay to msleep in the driver file mdfld_dsi_pkg_sender.c
>> in order to prevent CPU busy looping in order to save CPU cycles as this is
>> considered bad form over sleeping the CPU for high resolution timer function
>> calls as this driver needs in order to function properly.
>
> The code paths are called with sender->lock spinlock held.
>
> BR,
> Jani.
>
>>
>> Signed-off-by: Nicholas Krause <xerofoify at gmail.com>
>> ---
>>  drivers/gpu/drm/gma500/mdfld_dsi_pkg_sender.c | 15 +++++----------
>>  1 file changed, 5 insertions(+), 10 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/gma500/mdfld_dsi_pkg_sender.c b/drivers/gpu/drm/gma500/mdfld_dsi_pkg_sender.c
>> index 87885d8..77c656a 100644
>> --- a/drivers/gpu/drm/gma500/mdfld_dsi_pkg_sender.c
>> +++ b/drivers/gpu/drm/gma500/mdfld_dsi_pkg_sender.c
>> @@ -335,13 +335,11 @@ static int send_pkg_prepare(struct mdfld_dsi_pkg_sender *sender, u8 data_type,
>>
>>       /*wait for 120 milliseconds in case exit_sleep_mode just be sent*/
>>       if (unlikely(cmd == DCS_ENTER_SLEEP_MODE)) {
>> -             /*TODO: replace it with msleep later*/
>> -             mdelay(120);
>> +             msleep(120);
>>       }
>>
>>       if (unlikely(cmd == DCS_EXIT_SLEEP_MODE)) {
>> -             /*TODO: replace it with msleep later*/
>> -             mdelay(120);
>> +             msleep(120);
>>       }
>>       return 0;
>>  }
>> @@ -364,15 +362,12 @@ static int send_pkg_done(struct mdfld_dsi_pkg_sender *sender, u8 data_type,
>>       /*update panel status*/
>>       if (unlikely(cmd == DCS_ENTER_SLEEP_MODE)) {
>>               sender->panel_mode |= MDFLD_DSI_PANEL_MODE_SLEEP;
>> -             /*TODO: replace it with msleep later*/
>> -             mdelay(120);
>> +             msleep(120);
>>       } else if (unlikely(cmd == DCS_EXIT_SLEEP_MODE)) {
>>               sender->panel_mode &= ~MDFLD_DSI_PANEL_MODE_SLEEP;
>> -             /*TODO: replace it with msleep later*/
>> -             mdelay(120);
>> +             msleep(120);
>>       } else if (unlikely(cmd == DCS_SOFT_RESET)) {
>> -             /*TODO: replace it with msleep later*/
>> -             mdelay(5);
>> +             msleep(5);
>>       }
>>
>>       sender->status = MDFLD_DSI_PKG_SENDER_FREE;
>> --
>> 1.9.1
>>
>> _______________________________________________
>> dri-devel mailing list
>> dri-devel at lists.freedesktop.org
>> http://lists.freedesktop.org/mailman/listinfo/dri-devel
>
> --
> Jani Nikula, Intel Open Source Technology Center
Then surely we can remove this to dos or do we have to move all the
code to another coding scheme for this driver using mutuxes as they
don't loop.