Hi Kieran,
Thank you for the patch.
On Fri, Nov 26, 2021 at 10:15:17AM +0000, Kieran Bingham wrote:
> The debug reporting for the clock calculations was erroneously reporting
> the last calculation of fout, rather than the fout that was determined
> to have the least error, and therefore be the values chosen to operate
> with.
>
> Fix the reporting to show the correct output by storing the determined
> fout, along with the error value.
>
> Signed-off-by: Kieran Bingham <kieran.bingham+renesas@xxxxxxxxxxxxxxxx>
> ---
>
> I spent /way/ too long confused why my clock values didn't make sense
> before I noticed this.. :-(
Oops :-S Sorry about that.
> drivers/gpu/drm/rcar-du/rcar_mipi_dsi.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/rcar-du/rcar_mipi_dsi.c b/drivers/gpu/drm/rcar-du/rcar_mipi_dsi.c
> index e94245029f95..833f4480bdf3 100644
> --- a/drivers/gpu/drm/rcar-du/rcar_mipi_dsi.c
> +++ b/drivers/gpu/drm/rcar-du/rcar_mipi_dsi.c
> @@ -168,6 +168,7 @@ static int rcar_mipi_dsi_phtw_test(struct rcar_mipi_dsi *dsi, u32 phtw)
> */
>
> struct dsi_setup_info {
> + unsigned long fout;
> unsigned int err;
> u16 vco_cntrl;
> u16 prop_cntrl;
> @@ -247,6 +248,7 @@ static void rcar_mipi_dsi_parameters_calc(struct rcar_mipi_dsi *dsi,
> setup_info->m = m - 2;
> setup_info->n = n - 1;
> setup_info->err = err;
> + setup_info->fout = fout;
> if (err == 0)
> goto done;
> }
> @@ -256,7 +258,7 @@ static void rcar_mipi_dsi_parameters_calc(struct rcar_mipi_dsi *dsi,
> done:
> dev_dbg(dsi->dev,
> "%pC %lu Hz -> Fout %lu Hz (target %lu Hz, error %d.%02u%%), PLL M/N/DIV %u/%u/%u\n",
> - clk, fin, fout, fout_target, setup_info->err / 100,
> + clk, fin, setup_info->fout, fout_target, setup_info->err / 100,
We don't need the fout in the caller, so it could be a local variable
(best_fout for instance). I can however imagine that we the frequency
could become useful in the caller, so
Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
> setup_info->err % 100, setup_info->m,
> setup_info->n, setup_info->div);
> dev_dbg(dsi->dev,
--
Regards,
Laurent Pinchart
