atyfb: Fix bootup hangs on sparc64.

After commit 25edd6946a1d74e5e77813c2324a0908c68bcf9e ("sparc64: Get
rid of indirect p1275 PROM call buffer.")  we can't pass virtual
addresses >4GB to PROM calls.

Largely this is never necessary in drivers because we have a copy of
the entire PROM device tree in the kernel and a set of of_*()
interfaces to access it.

Unfortunately there were some lingering prom calls in the atyfb
driver, in particular prom_finddevice() was being called with an
on-stack address which could be anywhere.

This code is actually probing for information we already have, the
PROM choosen console output device is stored in of_console_device so
all of this nasty code consolidates into a one-line comparison.

Next we have some prom_getintdefault() calls which are trivially
transformed into the equivalent of_getintprop_default().

Special thanks to Fabio, who figured out exactly where the bootup
was hanging.  That made this bug trivial to fix.

Reported-by: Fabio M. Di NItto <fabbione@fabbione.net>
Reported-by: Sam Ravnborg <sam@ravnborg.org>
Reported-by: Frans van Berckel <fberckel@xs4all.nl>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Fabio M. Di NItto <fabbione@fabbione.net>

1 files changed, 5 insertions, 22 deletions

diff --git a/drivers/video/aty/atyfb_base.c b/drivers/video/aty/atyfb_base.c
index 5bf91236c701..5a3ce3ad1ec8 100644
--- a/drivers/video/aty/atyfb_base.c
+++ b/drivers/video/aty/atyfb_base.c
@@ -2969,10 +2969,8 @@ static int __devinit atyfb_setup_sparc(struct pci_dev *pdev,
 {
         struct atyfb_par *par = info->par;
         struct device_node *dp;
-        char prop[128];
-        phandle node;
-        int len, i, j, ret;
         u32 mem, chip_id;
+        int i, j, ret;
 
         /*
          * Map memory-mapped registers.
@@ -3088,23 +3086,8 @@ static int __devinit atyfb_setup_sparc(struct pci_dev *pdev,
                 aty_st_le32(MEM_CNTL, mem, par);
         }
 
-        /*
-         * If this is the console device, we will set default video
-         * settings to what the PROM left us with.
-         */
-        node = prom_getchild(prom_root_node);
-        node = prom_searchsiblings(node, "aliases");
-        if (node) {
-                len = prom_getproperty(node, "screen", prop, sizeof(prop));
-                if (len > 0) {
-                        prop[len] = '\0';
-                        node = prom_finddevice(prop);
-                } else
-                        node = 0;
-        }
-
         dp = pci_device_to_OF_node(pdev);
-        if (node == dp->phandle) {
+        if (dp == of_console_device) {
                 struct fb_var_screeninfo *var = &default_var;
                 unsigned int N, P, Q, M, T, R;
                 u32 v_total, h_total;
@@ -3112,9 +3095,9 @@ static int __devinit atyfb_setup_sparc(struct pci_dev *pdev,
                 u8 pll_regs[16];
                 u8 clock_cntl;
 
-                crtc.vxres = prom_getintdefault(node, "width", 1024);
-                crtc.vyres = prom_getintdefault(node, "height", 768);
-                var->bits_per_pixel = prom_getintdefault(node, "depth", 8);
+                crtc.vxres = of_getintprop_default(dp, "width", 1024);
+                crtc.vyres = of_getintprop_default(dp, "height", 768);
+                var->bits_per_pixel = of_getintprop_default(dp, "depth", 8);
                 var->xoffset = var->yoffset = 0;
                 crtc.h_tot_disp = aty_ld_le32(CRTC_H_TOTAL_DISP, par);
                 crtc.h_sync_strt_wid = aty_ld_le32(CRTC_H_SYNC_STRT_WID, par);