Sekhar, On Fri, Oct 26, 2012 at 1:05 PM, Sekhar Nori <[email protected]> wrote: > On 10/4/2012 7:23 PM, Prabhakar Lad wrote: >> Sekhar >> >> On Thu, Oct 4, 2012 at 12:43 PM, Sekhar Nori <[email protected]> wrote: >>> On 10/4/2012 10:22 AM, Prabhakar Lad wrote: >>>> Hi Sekhar, >>>> >>>> On Wed, Oct 3, 2012 at 4:08 PM, Sekhar Nori <[email protected]> wrote: >>>>> On 10/3/2012 12:05 PM, Prabhakar wrote: >>>>>> From: Lad, Prabhakar <[email protected]> >>>>>> >>>>>> while testing display on dm644x, for ED out-range signals >>>>>> was observed. This patch fixes appropriate clock setting >>>>>> for ED. >>>>> >>>>> Can you please clarify what you mean by "out range signal"? Are there >>>>> any user visible artifacts on the display? What was the clock being >>>>> provided earlier and what is the value after this patch? >>>>> >>>>> Also, is the issue severe enough that this patch should be applied to >>>>> stable tree as well? >>>>> >>>> Ideally a clock of 54Mhz is required for enhanced definition to >>>> work, which it was actually set to but while testing I noticed >>>> out-of-range signal. The out-of-range signal is often caused >>>> when the field rate is above the rate that the television will handle. >>>> When this is the case the TV or monitor displays "Out-Of-Range Signal". >>>> >>>> Reducing the clock fixed it. now the clock is set to 27Mhz. >>> >>> So, is the requirement for ED 54MHz or lower? Still trying to explain >>> myself how 27MHz is working where a 54MHz is required. I guess there is >>> also a lower limit on what the frequency should be? >>> >> Ideally its 54Mhz, but I see in the datasheet for AD7342/3 [1] it can also >> work at 27Mhz too. > > So, based on this discussion I think a better description would be: > > " > Fix the video clock setting when custom timings are used with pclock <= > 27MHz. Existing clock selection uses PLL2 mode which results in a 54MHz > clock where as using the MXI mode results in a 27MHz clock (which is the > one actually desired). > > This affects the Enhanced Definition (ED) support on DM644x. Without > this patch, out-range signals errors are were observed on the TV. An > out-of-range signal is often caused when the field rate is above the > rate that the television will handle. > " > > Is this accurate? In future, please try to be descriptive in patch > description as it will help understand what the patch is doing and why > (which in turn will lead to the patch getting accepted faster). > Looks good. I'll make sure to have descriptive commit message hence forth.
> Also I assume you need this patch in v3.7? Or can I send it for v3.8? > Since its a fix it would be good if its queued for v3.7. Regards, --Prabhakar > Thanks, > Sekhar _______________________________________________ Davinci-linux-open-source mailing list [email protected] http://linux.davincidsp.com/mailman/listinfo/davinci-linux-open-source
