Dear Philippe, you're right, clk_disable() & clk_enable() are necessary with STM32F4 SOC (not for STM32MP1). I'll revert this part of the patch. Many thanks -- Yannick Fertré | TINA: 166 7152 | Tel: +33 244027152 | Mobile: +33 620600270 Microcontrollers and Digital ICs Group | Microcontrolleurs Division On 5/10/19 6:40 PM, Philippe CORNU wrote: > Dear Yannick, > Thank you for your patch, > > In your patch, you have removed clk_disable() & clk_enable(). > Could you please double confirm ? > > thanks > Philippe :-) > > > On 5/10/19 5:03 PM, Yannick Fertré wrote: >> Clk_round_rate returns rounded clock without changing >> the hardware in any way. >> This function couldn't replace set_rate/get_rate calls. >> Todo comment has been removed & a new log inserted. >> >> Signed-off-by: Yannick Fertré <yannick.fertre@xxxxxx> >> --- >> drivers/gpu/drm/stm/ltdc.c | 10 +++------- >> 1 file changed, 3 insertions(+), 7 deletions(-) >> >> diff --git a/drivers/gpu/drm/stm/ltdc.c b/drivers/gpu/drm/stm/ltdc.c >> index 97912e2..2f8aa2e 100644 >> --- a/drivers/gpu/drm/stm/ltdc.c >> +++ b/drivers/gpu/drm/stm/ltdc.c >> @@ -507,20 +507,16 @@ static bool ltdc_crtc_mode_fixup(struct drm_crtc *crtc, >> struct ltdc_device *ldev = crtc_to_ltdc(crtc); >> int rate = mode->clock * 1000; >> >> - /* >> - * TODO clk_round_rate() does not work yet. When ready, it can >> - * be used instead of clk_set_rate() then clk_get_rate(). >> - */ >> - >> - clk_disable(ldev->pixel_clk); >> if (clk_set_rate(ldev->pixel_clk, rate) < 0) { >> DRM_ERROR("Cannot set rate (%dHz) for pixel clk\n", rate); >> return false; >> } >> - clk_enable(ldev->pixel_clk); >> >> adjusted_mode->clock = clk_get_rate(ldev->pixel_clk) / 1000; >> >> + DRM_DEBUG_DRIVER("requested clock %dkHz, adjusted clock %dkHz\n", >> + mode->clock, adjusted_mode->clock); >> + >> return true; >> } >> -- Yannick Fertré | TINA: 166 7152 | Tel: +33 244027152 | Mobile: +33 620600270 Microcontrollers and Digital ICs Group | Microcontrolleurs Division _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel