Hi
Am 03.05.20 um 17:42 schrieb Sam Ravnborg:
Hi Thomas.
On Wed, Apr 29, 2020 at 04:32:31PM +0200, Thomas Zimmermann wrote:
The framebuffer's pitch is now set in mgag200_set_offset().
Signed-off-by: Thomas Zimmermann tzimmermann@suse.de
I failed to follow this code.
Is it because of the line-offset calculation? MGAs want offsets in multiples of pixels, not bytes, and that factor depends on the value of cpp. I guess putting the calculation into a separate function will help with readability.
drivers/gpu/drm/mgag200/mgag200_mode.c | 41 +++++++++++++++++--------- 1 file changed, 27 insertions(+), 14 deletions(-)
diff --git a/drivers/gpu/drm/mgag200/mgag200_mode.c b/drivers/gpu/drm/mgag200/mgag200_mode.c index 92dee31f16c42..eb83e471d72fc 100644 --- a/drivers/gpu/drm/mgag200/mgag200_mode.c +++ b/drivers/gpu/drm/mgag200/mgag200_mode.c @@ -1003,6 +1003,32 @@ static void mgag200_set_mode_regs(struct mga_device *mdev, mga_crtc_set_plls(mdev, mode->clock); }
+static void mgag200_set_offset(struct mga_device *mdev,
const struct drm_framebuffer *fb)+{
- unsigned int offset;
- uint8_t crtc13, crtcext0;
- u8 bppshift;
- bppshift = mdev->bpp_shifts[fb->format->cpp[0] - 1];
Hmm, use of cpp is deprecated. But is continue to be used all over.
I try to move code without modifying it too much. Replacing cpp with some newer interface would obfuscate the moving to some extend. It's always a balancing act.
- offset = fb->pitches[0] / fb->format->cpp[0];
- if (fb->format->cpp[0] * 8 == 24)
offset = (offset * 3) >> (4 - bppshift);- else
offset = offset >> (4 - bppshift);- RREG_ECRT(0, crtcext0);
- crtc13 = offset & 0xff;
- crtcext0 &= ~GENMASK(5, 4);
- crtcext0 |= (offset & GENMASK(9, 8)) >> 4;
Lot's of hardcoded numbers. Could the reg file include these so you had more readable defined names?
Sure.
Best regards Thomas
- WREG_CRT(0x13, crtc13);
- WREG_ECRT(0x00, crtcext0);
+}
static int mga_crtc_mode_set(struct drm_crtc *crtc, struct drm_display_mode *mode, struct drm_display_mode *adjusted_mode, @@ -1011,7 +1037,6 @@ static int mga_crtc_mode_set(struct drm_crtc *crtc, struct drm_device *dev = crtc->dev; struct mga_device *mdev = dev->dev_private; const struct drm_framebuffer *fb = crtc->primary->fb;
- int pitch; int option = 0, option2 = 0; int i; unsigned char misc = 0;
@@ -1122,12 +1147,6 @@ static int mga_crtc_mode_set(struct drm_crtc *crtc, WREG_SEQ(3, 0); WREG_SEQ(4, 0xe);
- pitch = fb->pitches[0] / fb->format->cpp[0];
- if (fb->format->cpp[0] * 8 == 24)
pitch = (pitch * 3) >> (4 - bppshift);- else
pitch = pitch >> (4 - bppshift);- WREG_GFX(0, 0); WREG_GFX(1, 0); WREG_GFX(2, 0);
@@ -1144,20 +1163,15 @@ static int mga_crtc_mode_set(struct drm_crtc *crtc, WREG_CRT(13, 0); WREG_CRT(14, 0); WREG_CRT(15, 0);
WREG_CRT(19, pitch & 0xFF);
ext_vga[0] = 0;
/* TODO interlace */
ext_vga[0] |= (pitch & 0x300) >> 4; if (fb->format->cpp[0] * 8 == 24) ext_vga[3] = (((1 << bppshift) * 3) - 1) | 0x80; else ext_vga[3] = ((1 << bppshift) - 1) | 0x80; ext_vga[4] = 0;
WREG_ECRT(0, ext_vga[0]); WREG_ECRT(3, ext_vga[3]); WREG_ECRT(4, ext_vga[4]);
@@ -1171,8 +1185,6 @@ static int mga_crtc_mode_set(struct drm_crtc *crtc, WREG_ECRT(6, 0); }
- WREG_ECRT(0, ext_vga[0]);
- misc = RREG8(MGA_MISC_IN); misc |= MGAREG_MISC_IOADSEL | MGAREG_MISC_RAMMAPEN |
@@ -1180,6 +1192,7 @@ static int mga_crtc_mode_set(struct drm_crtc *crtc, WREG8(MGA_MISC_OUT, misc);
mga_crtc_do_set_base(mdev, fb, old_fb);
mgag200_set_offset(mdev, fb);
mgag200_set_mode_regs(mdev, mode);
Sam