sisfb: POST should fail if R/W test fails

Currently there is no indication if R/W test fails during POST. This can
happen e.g. when user plugs in a card with unsupported type of memory.
Since the driver will be unusable, it's better to fail the whole POST
if the memory cannot be configured properly.

Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Cc: Thomas Winischhofer <thomas@winischhofer.net>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

1 files changed, 17 insertions, 5 deletions

diff --git a/drivers/video/sis/sis_main.c b/drivers/video/sis/sis_main.c
index 2fb8c5a660fb..2c5de66dacf8 100644
--- a/drivers/video/sis/sis_main.c
+++ b/drivers/video/sis/sis_main.c
@@ -4627,11 +4627,11 @@ sisfb_post_xgi_rwtest(struct sis_video_info *ivideo, int starta,
         return 1;
 }
 
-static void __devinit
+static int __devinit
 sisfb_post_xgi_ramsize(struct sis_video_info *ivideo)
 {
         unsigned int buswidth, ranksize, channelab, mapsize;
-        int i, j, k, l;
+        int i, j, k, l, status;
         u8 reg, sr14;
         static const u8 dramsr13[12 * 5] = {
                 0x02, 0x0e, 0x0b, 0x80, 0x5d,
@@ -4673,7 +4673,7 @@ sisfb_post_xgi_ramsize(struct sis_video_info *ivideo)
                 SiS_SetReg(SISSR, 0x13, 0x35);
                 SiS_SetReg(SISSR, 0x14, 0x41);
                 /* TODO */
-                return;
+                return -ENOMEM;
         }
 
         /* Non-interleaving */
@@ -4835,6 +4835,7 @@ bail_out:
 
         j = (ivideo->chip == XGI_20) ? 5 : 9;
         k = (ivideo->chip == XGI_20) ? 12 : 4;
+        status = -EIO;
 
         for(i = 0; i < k; i++) {
 
@@ -4868,11 +4869,15 @@ bail_out:
                 SiS_SetRegANDOR(SISSR, 0x14, 0x0f, (reg & 0xf0));
                 sisfb_post_xgi_delay(ivideo, 1);
 
-                if(sisfb_post_xgi_rwtest(ivideo, j, ((reg >> 4) + channelab - 2 + 20), mapsize))
+                if (sisfb_post_xgi_rwtest(ivideo, j, ((reg >> 4) + channelab - 2 + 20), mapsize)) {
+                        status = 0;
                         break;
+                }
         }
 
         iounmap(ivideo->video_vbase);
+
+        return status;
 }
 
 static void __devinit
@@ -5648,6 +5653,7 @@ sisfb_post_xgi(struct pci_dev *pdev)
                 SiS_SetReg(SISSR, 0x14, bios[regb + 0xe0 + 8]);
 
         } else {
+                int err;
 
                 /* Set default mode, don't clear screen */
                 ivideo->SiS_Pr.SiS_UseOEM = false;
@@ -5661,10 +5667,16 @@ sisfb_post_xgi(struct pci_dev *pdev)
 
                 /* Disable read-cache */
                 SiS_SetRegAND(SISSR, 0x21, 0xdf);
-                sisfb_post_xgi_ramsize(ivideo);
+                err = sisfb_post_xgi_ramsize(ivideo);
                 /* Enable read-cache */
                 SiS_SetRegOR(SISSR, 0x21, 0x20);
 
+                if (err) {
+                        dev_err(&pdev->dev,
+                                "%s: RAM size detection failed: %d\n",
+                                __func__, err);
+                        return 0;
+                }
         }
 
 #if 0