Subject: [merged] drm-nouveau-bios-fix-a-bit-shift-error-introduced-by-457e77b.patch removed from -mm tree To: saproj@xxxxxxxxx,airlied@xxxxxxxxxx,bskeggs@xxxxxxxxxx,mm-commits@xxxxxxxxxxxxxxx From: akpm@xxxxxxxxxxxxxxxxxxxx Date: Mon, 21 Apr 2014 11:11:17 -0700 The patch titled Subject: drm/nouveau/bios: fix a bit shift error introduced by 457e77b has been removed from the -mm tree. Its filename was drm-nouveau-bios-fix-a-bit-shift-error-introduced-by-457e77b.patch This patch was dropped because it was merged into mainline or a subsystem tree ------------------------------------------------------ From: Sergei Antonov <saproj@xxxxxxxxx> Subject: drm/nouveau/bios: fix a bit shift error introduced by 457e77b 457e77b26428ab4a24 ("drm/nouveau/bios: add more checks to PRAMIN image fetching") added two checks applied to a value received from nv_rd32(bios, 0x619f04). But after this new piece of code is executed, the addr local variable does not hold the same value it used to hold before the commit. Here is what is was assigned in the original code: (u64)(nv_rd32(bios, 0x619f04) & 0xffffff00) << 8 in the committed code it ends up with this value: (u64)(nv_rd32(bios, 0x619f04) >> 8) << 8 These expressions are obviously not equivalent. My Nvidia video card does not show anything on the display when I boot a kernel containing this commit. The patch fixes the code so that the new checks are still done, but the side effect of an incorrect addr value is gone. Signed-off-by: Sergei Antonov <saproj@xxxxxxxxx> Cc: Ben Skeggs <bskeggs@xxxxxxxxxx> Cc: Dave Airlie <airlied@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- drivers/gpu/drm/nouveau/core/subdev/bios/base.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff -puN drivers/gpu/drm/nouveau/core/subdev/bios/base.c~drm-nouveau-bios-fix-a-bit-shift-error-introduced-by-457e77b drivers/gpu/drm/nouveau/core/subdev/bios/base.c --- a/drivers/gpu/drm/nouveau/core/subdev/bios/base.c~drm-nouveau-bios-fix-a-bit-shift-error-introduced-by-457e77b +++ a/drivers/gpu/drm/nouveau/core/subdev/bios/base.c @@ -109,7 +109,7 @@ nouveau_bios_shadow_pramin(struct nouvea return; } - addr = (u64)(addr >> 8) << 8; + addr = (u64)(addr & 0xffffff00) << 8; if (!addr) { addr = (u64)nv_rd32(bios, 0x001700) << 16; addr += 0xf0000; _ Patches currently in -mm which might be from saproj@xxxxxxxxx are -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html