Hi Am 10.09.19 um 16:01 schrieb Ville Syrjälä: > On Mon, Sep 09, 2019 at 04:06:33PM +0200, Thomas Zimmermann wrote: >> Support for vblank requires VSYNC to signal an interrupt, which is broken >> on Matrox chipsets. > > I don't remember there being anything wrong with the vsync interrupt. > What makes you think it's broken? > >> The workaround that is used here and in other free >> Matrox drivers is to program <linecomp> to the value of <vdisplay> and >> enable the VLINE interrupt. This triggers an interrupt at the same time >> when VSYNC begins. > > You're programming it to fire at start of vblank, not start of vsync. > >> >> VLINE uses separate registers for enabling and clearing pending interrupts. >> No extra syncronization between irq handler and the rest of the driver is >> required. >> >> Signed-off-by: Thomas Zimmermann <[email protected]> >> --- >> drivers/gpu/drm/mgag200/mgag200_drv.c | 1 + >> drivers/gpu/drm/mgag200/mgag200_drv.h | 1 + >> drivers/gpu/drm/mgag200/mgag200_main.c | 33 ++++++++++++++++++++ >> drivers/gpu/drm/mgag200/mgag200_mode.c | 42 +++++++++++++++++++++++--- >> 4 files changed, 73 insertions(+), 4 deletions(-) >> >> diff --git a/drivers/gpu/drm/mgag200/mgag200_drv.c >> b/drivers/gpu/drm/mgag200/mgag200_drv.c >> index 4f9df3b93598..cff265973154 100644 >> --- a/drivers/gpu/drm/mgag200/mgag200_drv.c >> +++ b/drivers/gpu/drm/mgag200/mgag200_drv.c >> @@ -67,6 +67,7 @@ static struct drm_driver driver = { >> .driver_features = DRIVER_GEM | DRIVER_MODESET, >> .load = mgag200_driver_load, >> .unload = mgag200_driver_unload, >> + .irq_handler = mgag200_irq_handler, >> .fops = &mgag200_driver_fops, >> .name = DRIVER_NAME, >> .desc = DRIVER_DESC, >> diff --git a/drivers/gpu/drm/mgag200/mgag200_drv.h >> b/drivers/gpu/drm/mgag200/mgag200_drv.h >> index 1c93f8dc08c7..88cf256d135f 100644 >> --- a/drivers/gpu/drm/mgag200/mgag200_drv.h >> +++ b/drivers/gpu/drm/mgag200/mgag200_drv.h >> @@ -195,6 +195,7 @@ void mgag200_modeset_fini(struct mga_device *mdev); >> /* mgag200_main.c */ >> int mgag200_driver_load(struct drm_device *dev, unsigned long flags); >> void mgag200_driver_unload(struct drm_device *dev); >> +irqreturn_t mgag200_irq_handler(int irq, void *arg); >> >> /* mgag200_i2c.c */ >> struct mga_i2c_chan *mgag200_i2c_create(struct drm_device *dev); >> diff --git a/drivers/gpu/drm/mgag200/mgag200_main.c >> b/drivers/gpu/drm/mgag200/mgag200_main.c >> index a9773334dedf..5941607796e8 100644 >> --- a/drivers/gpu/drm/mgag200/mgag200_main.c >> +++ b/drivers/gpu/drm/mgag200/mgag200_main.c >> @@ -10,7 +10,9 @@ >> >> #include <drm/drm_crtc_helper.h> >> #include <drm/drm_gem_framebuffer_helper.h> >> +#include <drm/drm_irq.h> >> #include <drm/drm_pci.h> >> +#include <drm/drm_vblank.h> >> >> #include "mgag200_drv.h" >> >> @@ -186,10 +188,18 @@ int mgag200_driver_load(struct drm_device *dev, >> unsigned long flags) >> } >> mdev->cursor.pixels_current = NULL; >> >> + r = drm_vblank_init(dev, 1); >> + if (r) >> + goto err_modeset; >> + >> r = drm_fbdev_generic_setup(mdev->dev, 0); >> if (r) >> goto err_modeset; >> >> + r = drm_irq_install(dev, dev->pdev->irq); >> + if (r) >> + goto err_modeset; >> + >> return 0; >> >> err_modeset: >> @@ -207,8 +217,31 @@ void mgag200_driver_unload(struct drm_device *dev) >> >> if (mdev == NULL) >> return; >> + drm_irq_uninstall(dev); >> mgag200_modeset_fini(mdev); >> drm_mode_config_cleanup(dev); >> mgag200_mm_fini(mdev); >> dev->dev_private = NULL; >> } >> + >> +irqreturn_t mgag200_irq_handler(int irq, void *arg) >> +{ >> + struct drm_device *dev = arg; >> + struct mga_device *mdev = dev->dev_private; >> + struct drm_crtc *crtc; >> + u32 status, iclear; >> + >> + status = RREG32(0x1e14); >> + >> + if (status & 0x00000020) { /* test <vlinepen> */ >> + drm_for_each_crtc(crtc, dev) { >> + drm_crtc_handle_vblank(crtc); >> + } > > A bit odd way to write that but as long this driver doesn't support > crtc2 it should be fine. > >> + iclear = RREG32(0x1e18); >> + iclear |= 0x00000020; /* set <vlineiclr> */ >> + WREG32(0x1e18, iclear); >> + return IRQ_HANDLED; >> + } >> + >> + return IRQ_NONE; >> +}; >> diff --git a/drivers/gpu/drm/mgag200/mgag200_mode.c >> b/drivers/gpu/drm/mgag200/mgag200_mode.c >> index 5e778b5f1a10..ffe5f15d0a7d 100644 >> --- a/drivers/gpu/drm/mgag200/mgag200_mode.c >> +++ b/drivers/gpu/drm/mgag200/mgag200_mode.c >> @@ -905,6 +905,7 @@ static int mga_crtc_mode_set(struct drm_crtc *crtc, >> const struct drm_framebuffer *fb = crtc->primary->fb; >> int hdisplay, hsyncstart, hsyncend, htotal; >> int vdisplay, vsyncstart, vsyncend, vtotal; >> + int linecomp; >> int pitch; >> int option = 0, option2 = 0; >> int i; >> @@ -1042,6 +1043,13 @@ static int mga_crtc_mode_set(struct drm_crtc *crtc, >> vsyncend = mode->vsync_end - 1; >> vtotal = mode->vtotal - 2; >> >> + /* The VSYNC interrupt is broken on Matrox chipsets. We use >> + * the VLINE interrupt instead. It triggers when the current >> + * linecomp has been reached. Therefore keep <linecomp> in >> + * sync with <vdisplay>. >> + */ >> + linecomp = vdisplay; > > I have an odd recollection that you want vdisplay+1 here if you > want the interrupt to fire at the correct time.
I double-checked and found that vdisplay is the value originally used by
this driver, by the fbdev driver and by Xorg's mga driver.
Best regards
Thomas
> Sine linecomp also resets the memory address counter to 0 you
> should probably see one bogus line at the bottom of the screen
> if my recollection of that +1 is correct.
>
> But maybe my memory is wrong.
>
>> +
>> WREG_GFX(0, 0);
>> WREG_GFX(1, 0);
>> WREG_GFX(2, 0);
>> @@ -1063,12 +1071,12 @@ static int mga_crtc_mode_set(struct drm_crtc *crtc,
>> ((vdisplay & 0x100) >> 7) |
>> ((vsyncstart & 0x100) >> 6) |
>> ((vdisplay & 0x100) >> 5) |
>> - ((vdisplay & 0x100) >> 4) | /* linecomp */
>> + ((linecomp & 0x100) >> 4) |
>> ((vtotal & 0x200) >> 4)|
>> ((vdisplay & 0x200) >> 3) |
>> ((vsyncstart & 0x200) >> 2));
>> WREG_CRT(9, ((vdisplay & 0x200) >> 4) |
>> - ((vdisplay & 0x200) >> 3));
>> + ((linecomp & 0x200) >> 3));
>> WREG_CRT(10, 0);
>> WREG_CRT(11, 0);
>> WREG_CRT(12, 0);
>> @@ -1083,7 +1091,7 @@ static int mga_crtc_mode_set(struct drm_crtc *crtc,
>> WREG_CRT(21, vdisplay & 0xFF);
>> WREG_CRT(22, (vtotal + 1) & 0xFF);
>> WREG_CRT(23, 0xc3);
>> - WREG_CRT(24, vdisplay & 0xFF);
>> + WREG_CRT(24, linecomp & 0xff);
>>
>> ext_vga[0] = 0;
>> ext_vga[5] = 0;
>> @@ -1099,7 +1107,7 @@ static int mga_crtc_mode_set(struct drm_crtc *crtc,
>> ((vdisplay & 0x400) >> 8) |
>> ((vdisplay & 0xc00) >> 7) |
>> ((vsyncstart & 0xc00) >> 5) |
>> - ((vdisplay & 0x400) >> 3);
>> + ((linecomp & 0x400) >> 3);
>> if (fb->format->cpp[0] * 8 == 24)
>> ext_vga[3] = (((1 << bppshift) * 3) - 1) | 0x80;
>> else
>> @@ -1411,6 +1419,30 @@ static void mga_crtc_disable(struct drm_crtc *crtc)
>> crtc->primary->fb = NULL;
>> }
>>
>> +static int mga_crtc_enable_vblank(struct drm_crtc *crtc)
>> +{
>> + struct drm_device *dev = crtc->dev;
>> + struct mga_device *mdev = dev->dev_private;
>> + u32 ien;
>> +
>> + ien = RREG32(0x1e1c);
>
> MGAREG_IEN?
>
>> + ien |= 0x00000020; /* set <vlineien> */
>> + WREG32(0x1e1c, ien);
>> +
>> + return 0;
>> +}
>> +
>> +static void mga_crtc_disable_vblank(struct drm_crtc *crtc)
>> +{
>> + struct drm_device *dev = crtc->dev;
>> + struct mga_device *mdev = dev->dev_private;
>> + u32 ien;
>> +
>> + ien = RREG32(0x1e1c);
>> + ien &= 0xffffffdf; /* clear <vlineien> */
>> + WREG32(0x1e1c, ien);
>> +}
>> +
>> /* These provide the minimum set of functions required to handle a CRTC */
>> static const struct drm_crtc_funcs mga_crtc_funcs = {
>> .cursor_set = mga_crtc_cursor_set,
>> @@ -1418,6 +1450,8 @@ static const struct drm_crtc_funcs mga_crtc_funcs = {
>> .gamma_set = mga_crtc_gamma_set,
>> .set_config = drm_crtc_helper_set_config,
>> .destroy = mga_crtc_destroy,
>> + .enable_vblank = mga_crtc_enable_vblank,
>> + .disable_vblank = mga_crtc_disable_vblank,
>> };
>>
>> static const struct drm_crtc_helper_funcs mga_helper_funcs = {
>> --
>> 2.23.0
>>
>> _______________________________________________
>> dri-devel mailing list
>> [email protected]
>> https://lists.freedesktop.org/mailman/listinfo/dri-devel
>
--
Thomas Zimmermann
Graphics Driver Developer
SUSE Linux GmbH, Maxfeldstrasse 5, 90409 Nuernberg, Germany
GF: Felix Imendörffer, Mary Higgins, Sri Rasiah
HRB 21284 (AG Nürnberg)
signature.asc
Description: OpenPGP digital signature
_______________________________________________ dri-devel mailing list [email protected] https://lists.freedesktop.org/mailman/listinfo/dri-devel
