On 06/09/2015 02:56 AM, Mauro Carvalho Chehab wrote: > Em Mon, 08 Jun 2015 17:20:20 -0700 > "Luis R. Rodriguez" <mcgrof@xxxxxxxxxxxxxxxx> escreveu: > >> From: "Luis R. Rodriguez" <mcgrof@xxxxxxxx> >> >> We are burrying direct access to MTRR code support on >> x86 in order to take advantage of PAT. In the future we >> also want to make the default behaviour of ioremap_nocache() >> to use strong UC, use of mtrr_add() on those systems >> would make write-combining void. >> >> In order to help both enable us to later make strong >> UC default and in order to phase out direct MTRR access >> code port the driver over to arch_phys_wc_add() and >> annotate that the device driver requires systems to >> boot with PAT disabled, with the nopat kernel parameter. >> >> This is a worthy comprmise given that the hardware is >> really rare these days, and perhaps only some lost souls >> in some third world country are expected to be using this >> feature of the device driver. >> >> Acked-by: Andy Walls <awalls@xxxxxxxxxxxxxxxx> >> Cc: Andy Walls <awalls@xxxxxxxxxxxxxxxx> >> Cc: Doug Ledford <dledford@xxxxxxxxxx> >> Cc: Mauro Carvalho Chehab <mchehab@xxxxxxxxxxxxxxx> > > Provided that you fix the issues below: > Acked-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxxxxxxx> > >> Cc: Andy Lutomirski <luto@xxxxxxxxxxxxxx> >> Cc: Suresh Siddha <sbsiddha@xxxxxxxxx> >> Cc: Ingo Molnar <mingo@xxxxxxx> >> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> >> Cc: Juergen Gross <jgross@xxxxxxxx> >> Cc: Daniel Vetter <daniel.vetter@xxxxxxxx> >> Cc: Dave Airlie <airlied@xxxxxxxxxx> >> Cc: Bjorn Helgaas <bhelgaas@xxxxxxxxxx> >> Cc: Antonino Daplas <adaplas@xxxxxxxxx> >> Cc: Jean-Christophe Plagniol-Villard <plagnioj@xxxxxxxxxxxx> >> Cc: Tomi Valkeinen <tomi.valkeinen@xxxxxx> >> Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> >> Cc: Arnd Bergmann <arnd@xxxxxxxx> >> Cc: Michael S. Tsirkin <mst@xxxxxxxxxx> >> Cc: Stefan Bader <stefan.bader@xxxxxxxxxxxxx> >> Cc: Ville Syrjälä <syrjala@xxxxxx> >> Cc: Mel Gorman <mgorman@xxxxxxx> >> Cc: Vlastimil Babka <vbabka@xxxxxxx> >> Cc: Borislav Petkov <bp@xxxxxxx> >> Cc: Davidlohr Bueso <dbueso@xxxxxxx> >> Cc: konrad.wilk@xxxxxxxxxx >> Cc: ville.syrjala@xxxxxxxxxxxxxxx >> Cc: david.vrabel@xxxxxxxxxx >> Cc: jbeulich@xxxxxxxx >> Cc: toshi.kani@xxxxxx >> Cc: Roger Pau Monné <roger.pau@xxxxxxxxxx> >> Cc: linux-fbdev@xxxxxxxxxxxxxxx >> Cc: linux-kernel@xxxxxxxxxxxxxxx >> Cc: ivtv-devel@xxxxxxxxxxxxxx >> Cc: linux-media@xxxxxxxxxxxxxxx >> Cc: xen-devel@xxxxxxxxxxxxxxxxxxx >> Signed-off-by: Luis R. Rodriguez <mcgrof@xxxxxxxx> >> --- >> drivers/media/pci/ivtv/Kconfig | 3 +++ >> drivers/media/pci/ivtv/ivtvfb.c | 58 ++++++++++++++++------------------------- >> 2 files changed, 26 insertions(+), 35 deletions(-) >> >> diff --git a/drivers/media/pci/ivtv/Kconfig b/drivers/media/pci/ivtv/Kconfig >> index dd6ee57e..b2a7f88 100644 >> --- a/drivers/media/pci/ivtv/Kconfig >> +++ b/drivers/media/pci/ivtv/Kconfig >> @@ -57,5 +57,8 @@ config VIDEO_FB_IVTV >> This is used in the Hauppauge PVR-350 card. There is a driver >> homepage at <http://www.ivtvdriver.org>. >> >> + If you have this hardware you will need to boot with PAT disabled >> + on your x86 systems, use the nopat kernel parameter. >> + > > Hmm... FB_IVTV is not hardware... it is framebuffer support for IVTV. > It is optional to use FB API for the video output port of this board, > instead of using V4L2 API. That's not true. It is hardware: it drives the video output OSD which overlays the video output. The reason it is optional is that it is hard to unload a framebuffer module and most people don't need it. So V4L2 drives the video output and ivtvfb drives the OSD overlay. So it is not a case of 'instead of'. > > I would say, instead, something like: > > "In order to use this module, you will need to boot with PAT disabled > on x86 systems, using the nopat kernel parameter." I do agree with this change, but that's because this module is optional and not for the reasons you mentioned above. Regards, Hans > >> To compile this driver as a module, choose M here: the >> module will be called ivtvfb. >> diff --git a/drivers/media/pci/ivtv/ivtvfb.c b/drivers/media/pci/ivtv/ivtvfb.c >> index 9ff1230..7685ae3 100644 >> --- a/drivers/media/pci/ivtv/ivtvfb.c >> +++ b/drivers/media/pci/ivtv/ivtvfb.c >> @@ -44,8 +44,8 @@ >> #include <linux/ivtvfb.h> >> #include <linux/slab.h> >> >> -#ifdef CONFIG_MTRR >> -#include <asm/mtrr.h> >> +#ifdef CONFIG_X86_64 >> +#include <asm/pat.h> >> #endif >> >> #include "ivtv-driver.h" >> @@ -155,12 +155,11 @@ struct osd_info { >> /* Buffer size */ >> u32 video_buffer_size; >> >> -#ifdef CONFIG_MTRR >> /* video_base rounded down as required by hardware MTRRs */ >> unsigned long fb_start_aligned_physaddr; >> /* video_base rounded up as required by hardware MTRRs */ >> unsigned long fb_end_aligned_physaddr; >> -#endif >> + int wc_cookie; >> >> /* Store the buffer offset */ >> int set_osd_coords_x; >> @@ -1099,6 +1098,8 @@ static int ivtvfb_init_vidmode(struct ivtv *itv) >> static int ivtvfb_init_io(struct ivtv *itv) >> { >> struct osd_info *oi = itv->osd_info; >> + /* Find the largest power of two that maps the whole buffer */ >> + int size_shift = 31; >> >> mutex_lock(&itv->serialize_lock); >> if (ivtv_init_on_first_open(itv)) { >> @@ -1132,29 +1133,16 @@ static int ivtvfb_init_io(struct ivtv *itv) >> oi->video_pbase, oi->video_vbase, >> oi->video_buffer_size / 1024); >> >> -#ifdef CONFIG_MTRR >> - { >> - /* Find the largest power of two that maps the whole buffer */ >> - int size_shift = 31; >> - >> - while (!(oi->video_buffer_size & (1 << size_shift))) { >> - size_shift--; >> - } >> - size_shift++; >> - oi->fb_start_aligned_physaddr = oi->video_pbase & ~((1 << size_shift) - 1); >> - oi->fb_end_aligned_physaddr = oi->video_pbase + oi->video_buffer_size; >> - oi->fb_end_aligned_physaddr += (1 << size_shift) - 1; >> - oi->fb_end_aligned_physaddr &= ~((1 << size_shift) - 1); >> - if (mtrr_add(oi->fb_start_aligned_physaddr, >> - oi->fb_end_aligned_physaddr - oi->fb_start_aligned_physaddr, >> - MTRR_TYPE_WRCOMB, 1) < 0) { >> - IVTVFB_INFO("disabled mttr\n"); >> - oi->fb_start_aligned_physaddr = 0; >> - oi->fb_end_aligned_physaddr = 0; >> - } >> - } >> -#endif >> - >> + while (!(oi->video_buffer_size & (1 << size_shift))) >> + size_shift--; >> + size_shift++; >> + oi->fb_start_aligned_physaddr = oi->video_pbase & ~((1 << size_shift) - 1); >> + oi->fb_end_aligned_physaddr = oi->video_pbase + oi->video_buffer_size; >> + oi->fb_end_aligned_physaddr += (1 << size_shift) - 1; >> + oi->fb_end_aligned_physaddr &= ~((1 << size_shift) - 1); >> + oi->wc_cookie = arch_phys_wc_add(oi->fb_start_aligned_physaddr, >> + oi->fb_end_aligned_physaddr - >> + oi->fb_start_aligned_physaddr); >> /* Blank the entire osd. */ >> memset_io(oi->video_vbase, 0, oi->video_buffer_size); >> >> @@ -1172,14 +1160,7 @@ static void ivtvfb_release_buffers (struct ivtv *itv) >> >> /* Release pseudo palette */ >> kfree(oi->ivtvfb_info.pseudo_palette); >> - >> -#ifdef CONFIG_MTRR >> - if (oi->fb_end_aligned_physaddr) { >> - mtrr_del(-1, oi->fb_start_aligned_physaddr, >> - oi->fb_end_aligned_physaddr - oi->fb_start_aligned_physaddr); >> - } >> -#endif >> - >> + arch_phys_wc_del(oi->wc_cookie); >> kfree(oi); >> itv->osd_info = NULL; >> } >> @@ -1284,6 +1265,13 @@ static int __init ivtvfb_init(void) >> int registered = 0; >> int err; >> >> +#ifdef CONFIG_X86_64 >> + if (WARN(pat_enabled(), >> + "ivtvfb needs PAT disabled, boot with nopat kernel parameter\n")) { >> + return EINVAL; > > Errors are always negative. So: > return -EINVAL > > Or, perhaps, -ENODEV. > >> + } >> +#endif >> + >> if (ivtvfb_card_id < -1 || ivtvfb_card_id >= IVTV_MAX_CARDS) { >> printk(KERN_ERR "ivtvfb: ivtvfb_card_id parameter is out of range (valid range: -1 - %d)\n", >> IVTV_MAX_CARDS - 1); > -- > To unsubscribe from this list: send the line "unsubscribe linux-media" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
