| Message ID | 20160826143045.7386-1-marex@denx.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Am Freitag, den 26.08.2016, 16:30 +0200 schrieb Marek Vasut: > Allocate the framebuffer memory as coherent, otherwise the framebuffer > will suffer from artifacts when displaying scrolling text or video. > This can be replicated on i.MX6SX (armv7), which has more complex memory > architecture compared to the i.MX23/28 (armv5). > > Signed-off-by: Marek Vasut <marex@denx.de> > Cc: Tomi Valkeinen <tomi.valkeinen@ti.com> > Cc: Fabio Estevam <fabio.estevam@nxp.com> > Cc: Lucas Stach <l.stach@pengutronix.de> > Cc: Shawn Guo <shawnguo@kernel.org> > --- > drivers/video/fbdev/mxsfb.c | 10 ++++++---- > 1 file changed, 6 insertions(+), 4 deletions(-) > > diff --git a/drivers/video/fbdev/mxsfb.c b/drivers/video/fbdev/mxsfb.c > index 4e6608c..bd1a310 100644 > --- a/drivers/video/fbdev/mxsfb.c > +++ b/drivers/video/fbdev/mxsfb.c > @@ -800,6 +800,7 @@ static int mxsfb_init_fbinfo(struct mxsfb_info *host, > struct fb_videomode *vmode) > { > int ret; > + struct device *dev = &host->pdev->dev; > struct fb_info *fb_info = &host->fb_info; > struct fb_var_screeninfo *var = &fb_info->var; > dma_addr_t fb_phys; > @@ -825,12 +826,11 @@ static int mxsfb_init_fbinfo(struct mxsfb_info *host, > > /* Memory allocation for framebuffer */ > fb_size = SZ_2M; > - fb_virt = alloc_pages_exact(fb_size, GFP_DMA); > + fb_virt = dma_alloc_coherent(dev, PAGE_ALIGN(fb_size), &fb_phys, > + GFP_KERNEL); You probably want writecombined memory here instead of coherent. Using coherent memory for framebuffers sucks performance wise. > if (!fb_virt) > return -ENOMEM; > > - fb_phys = virt_to_phys(fb_virt); > - > fb_info->fix.smem_start = fb_phys; > fb_info->screen_base = fb_virt; > fb_info->screen_size = fb_info->fix.smem_len = fb_size; > @@ -843,9 +843,11 @@ static int mxsfb_init_fbinfo(struct mxsfb_info *host, > > static void mxsfb_free_videomem(struct mxsfb_info *host) > { > + struct device *dev = &host->pdev->dev; > struct fb_info *fb_info = &host->fb_info; > > - free_pages_exact(fb_info->screen_base, fb_info->fix.smem_len); > + dma_free_coherent(dev, fb_info->screen_size, fb_info->screen_base, > + fb_info->fix.smem_start); > } > > static const struct platform_device_id mxsfb_devtype[] = { -- To unsubscribe from this list: send the line "unsubscribe linux-fbdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 08/26/2016 04:38 PM, Lucas Stach wrote: > Am Freitag, den 26.08.2016, 16:30 +0200 schrieb Marek Vasut: >> Allocate the framebuffer memory as coherent, otherwise the framebuffer >> will suffer from artifacts when displaying scrolling text or video. >> This can be replicated on i.MX6SX (armv7), which has more complex memory >> architecture compared to the i.MX23/28 (armv5). >> >> Signed-off-by: Marek Vasut <marex@denx.de> >> Cc: Tomi Valkeinen <tomi.valkeinen@ti.com> >> Cc: Fabio Estevam <fabio.estevam@nxp.com> >> Cc: Lucas Stach <l.stach@pengutronix.de> >> Cc: Shawn Guo <shawnguo@kernel.org> >> --- >> drivers/video/fbdev/mxsfb.c | 10 ++++++---- >> 1 file changed, 6 insertions(+), 4 deletions(-) >> >> diff --git a/drivers/video/fbdev/mxsfb.c b/drivers/video/fbdev/mxsfb.c >> index 4e6608c..bd1a310 100644 >> --- a/drivers/video/fbdev/mxsfb.c >> +++ b/drivers/video/fbdev/mxsfb.c >> @@ -800,6 +800,7 @@ static int mxsfb_init_fbinfo(struct mxsfb_info *host, >> struct fb_videomode *vmode) >> { >> int ret; >> + struct device *dev = &host->pdev->dev; >> struct fb_info *fb_info = &host->fb_info; >> struct fb_var_screeninfo *var = &fb_info->var; >> dma_addr_t fb_phys; >> @@ -825,12 +826,11 @@ static int mxsfb_init_fbinfo(struct mxsfb_info *host, >> >> /* Memory allocation for framebuffer */ >> fb_size = SZ_2M; >> - fb_virt = alloc_pages_exact(fb_size, GFP_DMA); >> + fb_virt = dma_alloc_coherent(dev, PAGE_ALIGN(fb_size), &fb_phys, >> + GFP_KERNEL); > > You probably want writecombined memory here instead of coherent. Using > coherent memory for framebuffers sucks performance wise. Ah, true. That'd be dma_{alloc,free}_wc() , right ?
diff --git a/drivers/video/fbdev/mxsfb.c b/drivers/video/fbdev/mxsfb.c index 4e6608c..bd1a310 100644 --- a/drivers/video/fbdev/mxsfb.c +++ b/drivers/video/fbdev/mxsfb.c @@ -800,6 +800,7 @@ static int mxsfb_init_fbinfo(struct mxsfb_info *host, struct fb_videomode *vmode) { int ret; + struct device *dev = &host->pdev->dev; struct fb_info *fb_info = &host->fb_info; struct fb_var_screeninfo *var = &fb_info->var; dma_addr_t fb_phys; @@ -825,12 +826,11 @@ static int mxsfb_init_fbinfo(struct mxsfb_info *host, /* Memory allocation for framebuffer */ fb_size = SZ_2M; - fb_virt = alloc_pages_exact(fb_size, GFP_DMA); + fb_virt = dma_alloc_coherent(dev, PAGE_ALIGN(fb_size), &fb_phys, + GFP_KERNEL); if (!fb_virt) return -ENOMEM; - fb_phys = virt_to_phys(fb_virt); - fb_info->fix.smem_start = fb_phys; fb_info->screen_base = fb_virt; fb_info->screen_size = fb_info->fix.smem_len = fb_size; @@ -843,9 +843,11 @@ static int mxsfb_init_fbinfo(struct mxsfb_info *host, static void mxsfb_free_videomem(struct mxsfb_info *host) { + struct device *dev = &host->pdev->dev; struct fb_info *fb_info = &host->fb_info; - free_pages_exact(fb_info->screen_base, fb_info->fix.smem_len); + dma_free_coherent(dev, fb_info->screen_size, fb_info->screen_base, + fb_info->fix.smem_start); } static const struct platform_device_id mxsfb_devtype[] = {
Allocate the framebuffer memory as coherent, otherwise the framebuffer will suffer from artifacts when displaying scrolling text or video. This can be replicated on i.MX6SX (armv7), which has more complex memory architecture compared to the i.MX23/28 (armv5). Signed-off-by: Marek Vasut <marex@denx.de> Cc: Tomi Valkeinen <tomi.valkeinen@ti.com> Cc: Fabio Estevam <fabio.estevam@nxp.com> Cc: Lucas Stach <l.stach@pengutronix.de> Cc: Shawn Guo <shawnguo@kernel.org> --- drivers/video/fbdev/mxsfb.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-)