* [PATCH v4 1/4] video: fbdev: atyfb: only use ioremap_uc() on i386 and ia64 [not found] <20230308130710.368085-1-bhe@redhat.com> @ 2023-03-08 13:07 ` Baoquan He 2023-03-08 20:01 ` Luis Chamberlain 0 siblings, 1 reply; 5+ messages in thread From: Baoquan He @ 2023-03-08 13:07 UTC (permalink / raw) To: linux-kernel Cc: linux-arch, linux-mm, arnd, mpe, geert, mcgrof, hch, Baoquan He, Helge Deller, Thomas Zimmermann, Christophe Leroy, linux-fbdev, dri-devel From: Arnd Bergmann <arnd@arndb.de> ioremap_uc() is only meaningful on old x86-32 systems with the PAT extension, and on ia64 with its slightly unconventional ioremap() behavior, everywhere else this is the same as ioremap() anyway. Change the only driver that still references ioremap_uc() to only do so on x86-32/ia64 in order to allow removing that interface at some point in the future for the other architectures. On some architectures, ioremap_uc() just returns NULL, changing the driver to call ioremap() means that they now have a chance of working correctly. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Baoquan He <bhe@redhat.com> Cc: Helge Deller <deller@gmx.de> Cc: Thomas Zimmermann <tzimmermann@suse.de> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: linux-fbdev@vger.kernel.org Cc: dri-devel@lists.freedesktop.org --- drivers/video/fbdev/aty/atyfb_base.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/video/fbdev/aty/atyfb_base.c b/drivers/video/fbdev/aty/atyfb_base.c index b02e4e645035..6553c71b113f 100644 --- a/drivers/video/fbdev/aty/atyfb_base.c +++ b/drivers/video/fbdev/aty/atyfb_base.c @@ -3440,11 +3440,15 @@ static int atyfb_setup_generic(struct pci_dev *pdev, struct fb_info *info, } info->fix.mmio_start = raddr; +#if defined(__i386__) || defined(__ia64__) /* * By using strong UC we force the MTRR to never have an * effect on the MMIO region on both non-PAT and PAT systems. */ par->ati_regbase = ioremap_uc(info->fix.mmio_start, 0x1000); +#else + par->ati_regbase = ioremap(info->fix.mmio_start, 0x1000); +#endif if (par->ati_regbase == NULL) return -ENOMEM; -- 2.34.1 ^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH v4 1/4] video: fbdev: atyfb: only use ioremap_uc() on i386 and ia64 2023-03-08 13:07 ` [PATCH v4 1/4] video: fbdev: atyfb: only use ioremap_uc() on i386 and ia64 Baoquan He @ 2023-03-08 20:01 ` Luis Chamberlain 2023-03-08 21:34 ` Arnd Bergmann 2023-03-08 22:48 ` Ondrej Zary 0 siblings, 2 replies; 5+ messages in thread From: Luis Chamberlain @ 2023-03-08 20:01 UTC (permalink / raw) To: Baoquan He Cc: linux-kernel, linux-arch, linux-mm, arnd, mpe, geert, hch, Helge Deller, Thomas Zimmermann, Christophe Leroy, linux-fbdev, dri-devel On Wed, Mar 08, 2023 at 09:07:07PM +0800, Baoquan He wrote: > From: Arnd Bergmann <arnd@arndb.de> > > ioremap_uc() is only meaningful on old x86-32 systems with the PAT > extension, and on ia64 with its slightly unconventional ioremap() > behavior, everywhere else this is the same as ioremap() anyway. > > Change the only driver that still references ioremap_uc() to only do so > on x86-32/ia64 in order to allow removing that interface at some > point in the future for the other architectures. > > On some architectures, ioremap_uc() just returns NULL, changing > the driver to call ioremap() means that they now have a chance > of working correctly. > > Signed-off-by: Arnd Bergmann <arnd@arndb.de> > Signed-off-by: Baoquan He <bhe@redhat.com> > Cc: Helge Deller <deller@gmx.de> > Cc: Thomas Zimmermann <tzimmermann@suse.de> > Cc: Christophe Leroy <christophe.leroy@csgroup.eu> > Cc: linux-fbdev@vger.kernel.org > Cc: dri-devel@lists.freedesktop.org Reviewed-by: Luis Chamberlain <mcgrof@kernel.org> Is anyone using this driver these days? How often do fbdev drivers get audited to see what can be nuked? Luis ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH v4 1/4] video: fbdev: atyfb: only use ioremap_uc() on i386 and ia64 2023-03-08 20:01 ` Luis Chamberlain @ 2023-03-08 21:34 ` Arnd Bergmann 2023-03-08 21:49 ` Helge Deller 2023-03-08 22:48 ` Ondrej Zary 1 sibling, 1 reply; 5+ messages in thread From: Arnd Bergmann @ 2023-03-08 21:34 UTC (permalink / raw) To: Luis Chamberlain, Baoquan He Cc: linux-kernel, Linux-Arch, linux-mm, Michael Ellerman, Geert Uytterhoeven, Christoph Hellwig, Helge Deller, Thomas Zimmermann, Christophe Leroy, linux-fbdev, dri-devel 0On Wed, Mar 8, 2023, at 21:01, Luis Chamberlain wrote: > On Wed, Mar 08, 2023 at 09:07:07PM +0800, Baoquan He wrote: >> From: Arnd Bergmann <arnd@arndb.de> >> >> ioremap_uc() is only meaningful on old x86-32 systems with the PAT >> extension, and on ia64 with its slightly unconventional ioremap() >> behavior, everywhere else this is the same as ioremap() anyway. >> >> Change the only driver that still references ioremap_uc() to only do so >> on x86-32/ia64 in order to allow removing that interface at some >> point in the future for the other architectures. >> >> On some architectures, ioremap_uc() just returns NULL, changing >> the driver to call ioremap() means that they now have a chance >> of working correctly. >> >> Signed-off-by: Arnd Bergmann <arnd@arndb.de> >> Signed-off-by: Baoquan He <bhe@redhat.com> >> Cc: Helge Deller <deller@gmx.de> >> Cc: Thomas Zimmermann <tzimmermann@suse.de> >> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> >> Cc: linux-fbdev@vger.kernel.org >> Cc: dri-devel@lists.freedesktop.org > > Reviewed-by: Luis Chamberlain <mcgrof@kernel.org> > > Is anyone using this driver these days? How often do fbdev drivers get > audited to see what can be nuked? Geert already mentioned that this one is likely used on old powermac systems. I think my arm boardfile removal orphaned some other fbdev drivers though. I removed the ones that can no longer be enabled, but think a bunch of other ones are still selectable but have no platform_device definition or DT support: FB_PXA168, FB_DA8XX, FB_MX3, and MMP_FB. These four platforms are all still supported with DT, but over time it gets less likely that anyone is still interested in adding DT support to the fbdev drivers. Arnd ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH v4 1/4] video: fbdev: atyfb: only use ioremap_uc() on i386 and ia64 2023-03-08 21:34 ` Arnd Bergmann @ 2023-03-08 21:49 ` Helge Deller 0 siblings, 0 replies; 5+ messages in thread From: Helge Deller @ 2023-03-08 21:49 UTC (permalink / raw) To: Arnd Bergmann, Luis Chamberlain, Baoquan He Cc: linux-kernel, Linux-Arch, linux-mm, Michael Ellerman, Geert Uytterhoeven, Christoph Hellwig, Thomas Zimmermann, Christophe Leroy, linux-fbdev, dri-devel On 3/8/23 22:34, Arnd Bergmann wrote: > 0On Wed, Mar 8, 2023, at 21:01, Luis Chamberlain wrote: >> On Wed, Mar 08, 2023 at 09:07:07PM +0800, Baoquan He wrote: >>> From: Arnd Bergmann <arnd@arndb.de> >>> >>> ioremap_uc() is only meaningful on old x86-32 systems with the PAT >>> extension, and on ia64 with its slightly unconventional ioremap() >>> behavior, everywhere else this is the same as ioremap() anyway. >>> >>> Change the only driver that still references ioremap_uc() to only do so >>> on x86-32/ia64 in order to allow removing that interface at some >>> point in the future for the other architectures. >>> >>> On some architectures, ioremap_uc() just returns NULL, changing >>> the driver to call ioremap() means that they now have a chance >>> of working correctly. >>> >>> Signed-off-by: Arnd Bergmann <arnd@arndb.de> >>> Signed-off-by: Baoquan He <bhe@redhat.com> >>> Cc: Helge Deller <deller@gmx.de> >>> Cc: Thomas Zimmermann <tzimmermann@suse.de> >>> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> >>> Cc: linux-fbdev@vger.kernel.org >>> Cc: dri-devel@lists.freedesktop.org >> >> Reviewed-by: Luis Chamberlain <mcgrof@kernel.org> >> >> Is anyone using this driver these days? How often do fbdev drivers get >> audited to see what can be nuked? > > Geert already mentioned that this one is likely used on old > powermac systems. and the latest generation of parisc machines use it too. In addition, on parisc machines it's also important to map all io-space memory uncacheable. Since ioremap() takes care of it anyway, the ioremap_uc() was simply referencing the call to ioremap(). Helge > I think my arm boardfile removal orphaned > some other fbdev drivers though. I removed the ones that can > no longer be enabled, but think a bunch of other ones > are still selectable but have no platform_device definition > or DT support: FB_PXA168, FB_DA8XX, FB_MX3, and MMP_FB. > > These four platforms are all still supported with DT, but > over time it gets less likely that anyone is still interested > in adding DT support to the fbdev drivers. > > Arnd ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH v4 1/4] video: fbdev: atyfb: only use ioremap_uc() on i386 and ia64 2023-03-08 20:01 ` Luis Chamberlain 2023-03-08 21:34 ` Arnd Bergmann @ 2023-03-08 22:48 ` Ondrej Zary 1 sibling, 0 replies; 5+ messages in thread From: Ondrej Zary @ 2023-03-08 22:48 UTC (permalink / raw) To: Luis Chamberlain Cc: Baoquan He, linux-kernel, linux-arch, linux-mm, arnd, mpe, geert, hch, Helge Deller, Thomas Zimmermann, Christophe Leroy, linux-fbdev, dri-devel On Wednesday 08 March 2023 21:01:09 Luis Chamberlain wrote: > On Wed, Mar 08, 2023 at 09:07:07PM +0800, Baoquan He wrote: > > From: Arnd Bergmann <arnd@arndb.de> > > > > ioremap_uc() is only meaningful on old x86-32 systems with the PAT > > extension, and on ia64 with its slightly unconventional ioremap() > > behavior, everywhere else this is the same as ioremap() anyway. > > > > Change the only driver that still references ioremap_uc() to only do so > > on x86-32/ia64 in order to allow removing that interface at some > > point in the future for the other architectures. > > > > On some architectures, ioremap_uc() just returns NULL, changing > > the driver to call ioremap() means that they now have a chance > > of working correctly. > > > > Signed-off-by: Arnd Bergmann <arnd@arndb.de> > > Signed-off-by: Baoquan He <bhe@redhat.com> > > Cc: Helge Deller <deller@gmx.de> > > Cc: Thomas Zimmermann <tzimmermann@suse.de> > > Cc: Christophe Leroy <christophe.leroy@csgroup.eu> > > Cc: linux-fbdev@vger.kernel.org > > Cc: dri-devel@lists.freedesktop.org > > Reviewed-by: Luis Chamberlain <mcgrof@kernel.org> > > Is anyone using this driver these days? How often do fbdev drivers get > audited to see what can be nuked? Older servers have integrated ATI Rage XL chips and this is the only driver for it. -- Ondrej Zary ^ permalink raw reply [flat|nested] 5+ messages in thread
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2023-03-08 13:07 ` [PATCH v4 1/4] video: fbdev: atyfb: only use ioremap_uc() on i386 and ia64 Baoquan He
2023-03-08 20:01 ` Luis Chamberlain
2023-03-08 21:34 ` Arnd Bergmann
2023-03-08 21:49 ` Helge Deller
2023-03-08 22:48 ` Ondrej Zary
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