Merge branch 'drm-fixes' of git://people.freedesktop.org/~airlied/linux

Pull drm fixes from Dave Airlie:
 "Nothing major, one core oops fixes, some radeon oops fixes, some sti
  driver fixups, msm driver fixes and a minor Kconfig update for the ww
  mutex debugging"

* 'drm-fixes' of git://people.freedesktop.org/~airlied/linux:
  drm/ast: Add missing entry to dclk_table[]
  drm: fix division-by-zero on dumb_create()
  ww-mutex: clarify help text for DEBUG_WW_MUTEX_SLOWPATH
  radeon: Test for PCI root bus before assuming bus->self
  drm/radeon: handle broken disabled rb mask gracefully (6xx/7xx) (v2)
  drm/radeon: save/restore the PD addr on suspend/resume
  drm/msm: Fix missing unlock on error in msm_fbdev_create()
  drm/msm: fix compile error for non-dt builds
  drm/msm/mdp4: request vblank during modeset
  drm/msm: avoid flood of kernel logs on faults
  drm: sti: Add missing dependency on RESET_CONTROLLER
  drm: sti: Make of_device_id array const
  drm: sti: Fix return value check in sti_drm_platform_probe()
  drm: sti: hda: fix return value check in sti_hda_probe()
  drm: sti: hdmi: fix return value check in sti_hdmi_probe()
  drm: sti: tvout: fix return value check in sti_tvout_probe()

18 files changed, 92 insertions, 65 deletions

diff --git a/drivers/gpu/drm/ast/ast_tables.h b/drivers/gpu/drm/ast/ast_tables.h
index 4c761dcea972..05c01ea85294 100644
--- a/drivers/gpu/drm/ast/ast_tables.h
+++ b/drivers/gpu/drm/ast/ast_tables.h
@@ -99,6 +99,7 @@ static struct ast_vbios_dclk_info dclk_table[] = {
         {0x25, 0x65, 0x80},                                     /* 16: VCLK88.75    */
         {0x77, 0x58, 0x80},                                     /* 17: VCLK119      */
         {0x32, 0x67, 0x80},                                 /* 18: VCLK85_5     */
+        {0x6a, 0x6d, 0x80},                                     /* 19: VCLK97_75        */
 };
 
 static struct ast_vbios_stdtable vbios_stdtable[] = {
diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
index fa2be249999c..90e773019eac 100644
--- a/drivers/gpu/drm/drm_crtc.c
+++ b/drivers/gpu/drm/drm_crtc.c
@@ -4696,8 +4696,9 @@ int drm_mode_create_dumb_ioctl(struct drm_device *dev,
                 return -EINVAL;
 
         /* overflow checks for 32bit size calculations */
+        /* NOTE: DIV_ROUND_UP() can overflow */
         cpp = DIV_ROUND_UP(args->bpp, 8);
-        if (cpp > 0xffffffffU / args->width)
+        if (!cpp || cpp > 0xffffffffU / args->width)
                 return -EINVAL;
         stride = cpp * args->width;
         if (args->height > 0xffffffffU / stride)
diff --git a/drivers/gpu/drm/msm/mdp/mdp4/mdp4_crtc.c b/drivers/gpu/drm/msm/mdp/mdp4/mdp4_crtc.c
index 74cebb51e8c2..c6c80ea28c35 100644
--- a/drivers/gpu/drm/msm/mdp/mdp4/mdp4_crtc.c
+++ b/drivers/gpu/drm/msm/mdp/mdp4/mdp4_crtc.c
@@ -397,6 +397,7 @@ static void mdp4_crtc_prepare(struct drm_crtc *crtc)
         struct mdp4_crtc *mdp4_crtc = to_mdp4_crtc(crtc);
         DBG("%s", mdp4_crtc->name);
         /* make sure we hold a ref to mdp clks while setting up mode: */
+        drm_crtc_vblank_get(crtc);
         mdp4_enable(get_kms(crtc));
         mdp4_crtc_dpms(crtc, DRM_MODE_DPMS_OFF);
 }
@@ -407,6 +408,7 @@ static void mdp4_crtc_commit(struct drm_crtc *crtc)
         crtc_flush(crtc);
         /* drop the ref to mdp clk's that we got in prepare: */
         mdp4_disable(get_kms(crtc));
+        drm_crtc_vblank_put(crtc);
 }
 
 static int mdp4_crtc_mode_set_base(struct drm_crtc *crtc, int x, int y,
diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c
index b447c01ad89c..26ee80db17af 100644
--- a/drivers/gpu/drm/msm/msm_drv.c
+++ b/drivers/gpu/drm/msm/msm_drv.c
@@ -974,12 +974,11 @@ static int msm_pdev_probe(struct platform_device *pdev)
 
         for (i = 0; i < ARRAY_SIZE(devnames); i++) {
                 struct device *dev;
-                int ret;
 
                 dev = bus_find_device_by_name(&platform_bus_type,
                                 NULL, devnames[i]);
                 if (!dev) {
-                        dev_info(master, "still waiting for %s\n", devnames[i]);
+                        dev_info(&pdev->dev, "still waiting for %s\n", devnames[i]);
                         return -EPROBE_DEFER;
                 }
 
diff --git a/drivers/gpu/drm/msm/msm_fbdev.c b/drivers/gpu/drm/msm/msm_fbdev.c
index 9c5221ce391a..ab5bfd2d0ebf 100644
--- a/drivers/gpu/drm/msm/msm_fbdev.c
+++ b/drivers/gpu/drm/msm/msm_fbdev.c
@@ -143,7 +143,7 @@ static int msm_fbdev_create(struct drm_fb_helper *helper,
         ret = msm_gem_get_iova_locked(fbdev->bo, 0, &paddr);
         if (ret) {
                 dev_err(dev->dev, "failed to get buffer obj iova: %d\n", ret);
-                goto fail;
+                goto fail_unlock;
         }
 
         fbi = framebuffer_alloc(0, dev->dev);
diff --git a/drivers/gpu/drm/msm/msm_iommu.c b/drivers/gpu/drm/msm/msm_iommu.c
index 099af483fdf0..7acdaa5688b7 100644
--- a/drivers/gpu/drm/msm/msm_iommu.c
+++ b/drivers/gpu/drm/msm/msm_iommu.c
@@ -27,8 +27,8 @@ struct msm_iommu {
 static int msm_fault_handler(struct iommu_domain *iommu, struct device *dev,
                 unsigned long iova, int flags, void *arg)
 {
-        DBG("*** fault: iova=%08lx, flags=%d", iova, flags);
-        return -ENOSYS;
+        pr_warn_ratelimited("*** fault: iova=%08lx, flags=%d\n", iova, flags);
+        return 0;
 }
 
 static int msm_iommu_attach(struct msm_mmu *mmu, const char **names, int cnt)
diff --git a/drivers/gpu/drm/radeon/cik.c b/drivers/gpu/drm/radeon/cik.c
index 79a5a5519bd6..fa9565957f9d 100644
--- a/drivers/gpu/drm/radeon/cik.c
+++ b/drivers/gpu/drm/radeon/cik.c
@@ -5749,20 +5749,17 @@ static int cik_pcie_gart_enable(struct radeon_device *rdev)
         WREG32(0x15D8, 0);
         WREG32(0x15DC, 0);
 
-        /* empty context1-15 */
-        /* FIXME start with 4G, once using 2 level pt switch to full
-         * vm size space
-         */
+        /* restore context1-15 */
         /* set vm size, must be a multiple of 4 */
         WREG32(VM_CONTEXT1_PAGE_TABLE_START_ADDR, 0);
         WREG32(VM_CONTEXT1_PAGE_TABLE_END_ADDR, rdev->vm_manager.max_pfn);
         for (i = 1; i < 16; i++) {
                 if (i < 8)
                         WREG32(VM_CONTEXT0_PAGE_TABLE_BASE_ADDR + (i << 2),
-                               rdev->gart.table_addr >> 12);
+                               rdev->vm_manager.saved_table_addr[i]);
                 else
                         WREG32(VM_CONTEXT8_PAGE_TABLE_BASE_ADDR + ((i - 8) << 2),
-                               rdev->gart.table_addr >> 12);
+                               rdev->vm_manager.saved_table_addr[i]);
         }
 
         /* enable context1-15 */
@@ -5827,6 +5824,17 @@ static int cik_pcie_gart_enable(struct radeon_device *rdev)
  */
 static void cik_pcie_gart_disable(struct radeon_device *rdev)
 {
+        unsigned i;
+
+        for (i = 1; i < 16; ++i) {
+                uint32_t reg;
+                if (i < 8)
+                        reg = VM_CONTEXT0_PAGE_TABLE_BASE_ADDR + (i << 2);
+                else
+                        reg = VM_CONTEXT8_PAGE_TABLE_BASE_ADDR + ((i - 8) << 2);
+                rdev->vm_manager.saved_table_addr[i] = RREG32(reg);
+        }
+
         /* Disable all tables */
         WREG32(VM_CONTEXT0_CNTL, 0);
         WREG32(VM_CONTEXT1_CNTL, 0);
@@ -9555,6 +9563,9 @@ static void cik_pcie_gen3_enable(struct radeon_device *rdev)
         int ret, i;
         u16 tmp16;
 
+        if (pci_is_root_bus(rdev->pdev->bus))
+                return;
+
         if (radeon_pcie_gen2 == 0)
                 return;
 
@@ -9781,7 +9792,8 @@ static void cik_program_aspm(struct radeon_device *rdev)
                         if (orig != data)
                                 WREG32_PCIE_PORT(PCIE_LC_LINK_WIDTH_CNTL, data);
 
-                        if (!disable_clkreq) {
+                        if (!disable_clkreq &&
+                            !pci_is_root_bus(rdev->pdev->bus)) {
                                 struct pci_dev *root = rdev->pdev->bus->self;
                                 u32 lnkcap;
 
diff --git a/drivers/gpu/drm/radeon/ni.c b/drivers/gpu/drm/radeon/ni.c
index ba89375f197f..3faee58946dd 100644
--- a/drivers/gpu/drm/radeon/ni.c
+++ b/drivers/gpu/drm/radeon/ni.c
@@ -1271,7 +1271,7 @@ static int cayman_pcie_gart_enable(struct radeon_device *rdev)
                 WREG32(VM_CONTEXT0_PAGE_TABLE_START_ADDR + (i << 2), 0);
                 WREG32(VM_CONTEXT0_PAGE_TABLE_END_ADDR + (i << 2), rdev->vm_manager.max_pfn);
                 WREG32(VM_CONTEXT0_PAGE_TABLE_BASE_ADDR + (i << 2),
-                        rdev->gart.table_addr >> 12);
+                       rdev->vm_manager.saved_table_addr[i]);
         }
 
         /* enable context1-7 */
@@ -1303,6 +1303,13 @@ static int cayman_pcie_gart_enable(struct radeon_device *rdev)
 
 static void cayman_pcie_gart_disable(struct radeon_device *rdev)
 {
+        unsigned i;
+
+        for (i = 1; i < 8; ++i) {
+                rdev->vm_manager.saved_table_addr[i] = RREG32(
+                        VM_CONTEXT0_PAGE_TABLE_BASE_ADDR + (i << 2));
+        }
+
         /* Disable all tables */
         WREG32(VM_CONTEXT0_CNTL, 0);
         WREG32(VM_CONTEXT1_CNTL, 0);
diff --git a/drivers/gpu/drm/radeon/r600.c b/drivers/gpu/drm/radeon/r600.c
index e8bf0ea2dade..e616eb5f6e7a 100644
--- a/drivers/gpu/drm/radeon/r600.c
+++ b/drivers/gpu/drm/radeon/r600.c
@@ -1812,7 +1812,6 @@ static void r600_gpu_init(struct radeon_device *rdev)
 {
         u32 tiling_config;
         u32 ramcfg;
-        u32 cc_rb_backend_disable;
         u32 cc_gc_shader_pipe_config;
         u32 tmp;
         int i, j;
@@ -1939,29 +1938,20 @@ static void r600_gpu_init(struct radeon_device *rdev)
         }
         tiling_config |= BANK_SWAPS(1);
 
-        cc_rb_backend_disable = RREG32(CC_RB_BACKEND_DISABLE) & 0x00ff0000;
-        tmp = R6XX_MAX_BACKENDS -
-                r600_count_pipe_bits((cc_rb_backend_disable >> 16) & R6XX_MAX_BACKENDS_MASK);
-        if (tmp < rdev->config.r600.max_backends) {
-                rdev->config.r600.max_backends = tmp;
-        }
-
         cc_gc_shader_pipe_config = RREG32(CC_GC_SHADER_PIPE_CONFIG) & 0x00ffff00;
-        tmp = R6XX_MAX_PIPES -
-                r600_count_pipe_bits((cc_gc_shader_pipe_config >> 8) & R6XX_MAX_PIPES_MASK);
-        if (tmp < rdev->config.r600.max_pipes) {
-                rdev->config.r600.max_pipes = tmp;
-        }
-        tmp = R6XX_MAX_SIMDS -
-                r600_count_pipe_bits((cc_gc_shader_pipe_config >> 16) & R6XX_MAX_SIMDS_MASK);
-        if (tmp < rdev->config.r600.max_simds) {
-                rdev->config.r600.max_simds = tmp;
-        }
         tmp = rdev->config.r600.max_simds -
                 r600_count_pipe_bits((cc_gc_shader_pipe_config >> 16) & R6XX_MAX_SIMDS_MASK);
         rdev->config.r600.active_simds = tmp;
 
         disabled_rb_mask = (RREG32(CC_RB_BACKEND_DISABLE) >> 16) & R6XX_MAX_BACKENDS_MASK;
+        tmp = 0;
+        for (i = 0; i < rdev->config.r600.max_backends; i++)
+                tmp |= (1 << i);
+        /* if all the backends are disabled, fix it up here */
+        if ((disabled_rb_mask & tmp) == tmp) {
+                for (i = 0; i < rdev->config.r600.max_backends; i++)
+                        disabled_rb_mask &= ~(1 << i);
+        }
         tmp = (tiling_config & PIPE_TILING__MASK) >> PIPE_TILING__SHIFT;
         tmp = r6xx_remap_render_backend(rdev, tmp, rdev->config.r600.max_backends,
                                         R6XX_MAX_BACKENDS, disabled_rb_mask);
diff --git a/drivers/gpu/drm/radeon/radeon.h b/drivers/gpu/drm/radeon/radeon.h
index b281886f6f51..5f05b4c84338 100644
--- a/drivers/gpu/drm/radeon/radeon.h
+++ b/drivers/gpu/drm/radeon/radeon.h
@@ -915,6 +915,8 @@ struct radeon_vm_manager {
         u64                             vram_base_offset;
         /* is vm enabled? */
         bool                            enabled;
+        /* for hw to save the PD addr on suspend/resume */
+        uint32_t                        saved_table_addr[RADEON_NUM_VM];
 };
 
 /*
diff --git a/drivers/gpu/drm/radeon/rv770.c b/drivers/gpu/drm/radeon/rv770.c
index 2983f17ea1b3..d9f5ce715c9b 100644
--- a/drivers/gpu/drm/radeon/rv770.c
+++ b/drivers/gpu/drm/radeon/rv770.c
@@ -1177,7 +1177,6 @@ static void rv770_gpu_init(struct radeon_device *rdev)
         u32 hdp_host_path_cntl;
         u32 sq_dyn_gpr_size_simd_ab_0;
         u32 gb_tiling_config = 0;
-        u32 cc_rb_backend_disable = 0;
         u32 cc_gc_shader_pipe_config = 0;
         u32 mc_arb_ramcfg;
         u32 db_debug4, tmp;
@@ -1311,21 +1310,7 @@ static void rv770_gpu_init(struct radeon_device *rdev)
                 WREG32(SPI_CONFIG_CNTL, 0);
         }
 
-        cc_rb_backend_disable = RREG32(CC_RB_BACKEND_DISABLE) & 0x00ff0000;
-        tmp = R7XX_MAX_BACKENDS - r600_count_pipe_bits(cc_rb_backend_disable >> 16);
-        if (tmp < rdev->config.rv770.max_backends) {
-                rdev->config.rv770.max_backends = tmp;
-        }
-
         cc_gc_shader_pipe_config = RREG32(CC_GC_SHADER_PIPE_CONFIG) & 0xffffff00;
-        tmp = R7XX_MAX_PIPES - r600_count_pipe_bits((cc_gc_shader_pipe_config >> 8) & R7XX_MAX_PIPES_MASK);
-        if (tmp < rdev->config.rv770.max_pipes) {
-                rdev->config.rv770.max_pipes = tmp;
-        }
-        tmp = R7XX_MAX_SIMDS - r600_count_pipe_bits((cc_gc_shader_pipe_config >> 16) & R7XX_MAX_SIMDS_MASK);
-        if (tmp < rdev->config.rv770.max_simds) {
-                rdev->config.rv770.max_simds = tmp;
-        }
         tmp = rdev->config.rv770.max_simds -
                 r600_count_pipe_bits((cc_gc_shader_pipe_config >> 16) & R7XX_MAX_SIMDS_MASK);
         rdev->config.rv770.active_simds = tmp;
@@ -1348,6 +1333,14 @@ static void rv770_gpu_init(struct radeon_device *rdev)
         rdev->config.rv770.tiling_npipes = rdev->config.rv770.max_tile_pipes;
 
         disabled_rb_mask = (RREG32(CC_RB_BACKEND_DISABLE) >> 16) & R7XX_MAX_BACKENDS_MASK;
+        tmp = 0;
+        for (i = 0; i < rdev->config.rv770.max_backends; i++)
+                tmp |= (1 << i);
+        /* if all the backends are disabled, fix it up here */
+        if ((disabled_rb_mask & tmp) == tmp) {
+                for (i = 0; i < rdev->config.rv770.max_backends; i++)
+                        disabled_rb_mask &= ~(1 << i);
+        }
         tmp = (gb_tiling_config & PIPE_TILING__MASK) >> PIPE_TILING__SHIFT;
         tmp = r6xx_remap_render_backend(rdev, tmp, rdev->config.rv770.max_backends,
                                         R7XX_MAX_BACKENDS, disabled_rb_mask);
diff --git a/drivers/gpu/drm/radeon/si.c b/drivers/gpu/drm/radeon/si.c
index a1274a31405c..6bce40847753 100644
--- a/drivers/gpu/drm/radeon/si.c
+++ b/drivers/gpu/drm/radeon/si.c
@@ -4290,10 +4290,10 @@ static int si_pcie_gart_enable(struct radeon_device *rdev)
         for (i = 1; i < 16; i++) {
                 if (i < 8)
                         WREG32(VM_CONTEXT0_PAGE_TABLE_BASE_ADDR + (i << 2),
-                               rdev->gart.table_addr >> 12);
+                               rdev->vm_manager.saved_table_addr[i]);
                 else
                         WREG32(VM_CONTEXT8_PAGE_TABLE_BASE_ADDR + ((i - 8) << 2),
-                               rdev->gart.table_addr >> 12);
+                               rdev->vm_manager.saved_table_addr[i]);
         }
 
         /* enable context1-15 */
@@ -4325,6 +4325,17 @@ static int si_pcie_gart_enable(struct radeon_device *rdev)
 
 static void si_pcie_gart_disable(struct radeon_device *rdev)
 {
+        unsigned i;
+
+        for (i = 1; i < 16; ++i) {
+                uint32_t reg;
+                if (i < 8)
+                        reg = VM_CONTEXT0_PAGE_TABLE_BASE_ADDR + (i << 2);
+                else
+                        reg = VM_CONTEXT8_PAGE_TABLE_BASE_ADDR + ((i - 8) << 2);
+                rdev->vm_manager.saved_table_addr[i] = RREG32(reg);
+        }
+
         /* Disable all tables */
         WREG32(VM_CONTEXT0_CNTL, 0);
         WREG32(VM_CONTEXT1_CNTL, 0);
@@ -7177,6 +7188,9 @@ static void si_pcie_gen3_enable(struct radeon_device *rdev)
         int ret, i;
         u16 tmp16;
 
+        if (pci_is_root_bus(rdev->pdev->bus))
+                return;
+
         if (radeon_pcie_gen2 == 0)
                 return;
 
@@ -7454,7 +7468,8 @@ static void si_program_aspm(struct radeon_device *rdev)
                         if (orig != data)
                                 WREG32_PIF_PHY1(PB1_PIF_CNTL, data);
 
-                        if (!disable_clkreq) {
+                        if (!disable_clkreq &&
+                            !pci_is_root_bus(rdev->pdev->bus)) {
                                 struct pci_dev *root = rdev->pdev->bus->self;
                                 u32 lnkcap;
 
diff --git a/drivers/gpu/drm/sti/Kconfig b/drivers/gpu/drm/sti/Kconfig
index 2d9d4252d598..ae8850f3e63b 100644
--- a/drivers/gpu/drm/sti/Kconfig
+++ b/drivers/gpu/drm/sti/Kconfig
@@ -1,6 +1,7 @@
 config DRM_STI
         tristate "DRM Support for STMicroelectronics SoC stiH41x Series"
         depends on DRM && (SOC_STIH415 || SOC_STIH416 || ARCH_MULTIPLATFORM)
+        select RESET_CONTROLLER
         select DRM_KMS_HELPER
         select DRM_GEM_CMA_HELPER
         select DRM_KMS_CMA_HELPER
diff --git a/drivers/gpu/drm/sti/sti_drm_drv.c b/drivers/gpu/drm/sti/sti_drm_drv.c
index a7cc24917a96..223d93c3a05d 100644
--- a/drivers/gpu/drm/sti/sti_drm_drv.c
+++ b/drivers/gpu/drm/sti/sti_drm_drv.c
@@ -201,8 +201,8 @@ static int sti_drm_platform_probe(struct platform_device *pdev)
         master = platform_device_register_resndata(dev,
                         DRIVER_NAME "__master", -1,
                         NULL, 0, NULL, 0);
-        if (!master)
-                return -EINVAL;
+        if (IS_ERR(master))
+               return PTR_ERR(master);
 
         platform_set_drvdata(pdev, master);
         return 0;
diff --git a/drivers/gpu/drm/sti/sti_hda.c b/drivers/gpu/drm/sti/sti_hda.c
index 72d957f81c05..2ae9a9b73666 100644
--- a/drivers/gpu/drm/sti/sti_hda.c
+++ b/drivers/gpu/drm/sti/sti_hda.c
@@ -730,16 +730,16 @@ static int sti_hda_probe(struct platform_device *pdev)
                 return -ENOMEM;
         }
         hda->regs = devm_ioremap_nocache(dev, res->start, resource_size(res));
-        if (IS_ERR(hda->regs))
-                return PTR_ERR(hda->regs);
+        if (!hda->regs)
+                return -ENOMEM;
 
         res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
                         "video-dacs-ctrl");
         if (res) {
                 hda->video_dacs_ctrl = devm_ioremap_nocache(dev, res->start,
                                 resource_size(res));
-                if (IS_ERR(hda->video_dacs_ctrl))
-                        return PTR_ERR(hda->video_dacs_ctrl);
+                if (!hda->video_dacs_ctrl)
+                        return -ENOMEM;
         } else {
                 /* If no existing video-dacs-ctrl resource continue the probe */
                 DRM_DEBUG_DRIVER("No video-dacs-ctrl resource\n");
@@ -770,7 +770,7 @@ static int sti_hda_remove(struct platform_device *pdev)
         return 0;
 }
 
-static struct of_device_id hda_of_match[] = {
+static const struct of_device_id hda_of_match[] = {
         { .compatible = "st,stih416-hda", },
         { .compatible = "st,stih407-hda", },
         { /* end node */ }
diff --git a/drivers/gpu/drm/sti/sti_hdmi.c b/drivers/gpu/drm/sti/sti_hdmi.c
index 284e541d970d..ef93156a69c6 100644
--- a/drivers/gpu/drm/sti/sti_hdmi.c
+++ b/drivers/gpu/drm/sti/sti_hdmi.c
@@ -677,7 +677,7 @@ static const struct component_ops sti_hdmi_ops = {
         .unbind = sti_hdmi_unbind,
 };
 
-static struct of_device_id hdmi_of_match[] = {
+static const struct of_device_id hdmi_of_match[] = {
         {
                 .compatible = "st,stih416-hdmi",
                 .data = &tx3g0c55phy_ops,
@@ -713,8 +713,8 @@ static int sti_hdmi_probe(struct platform_device *pdev)
                 return -ENOMEM;
         }
         hdmi->regs = devm_ioremap_nocache(dev, res->start, resource_size(res));
-        if (IS_ERR(hdmi->regs))
-                return PTR_ERR(hdmi->regs);
+        if (!hdmi->regs)
+                return -ENOMEM;
 
         if (of_device_is_compatible(np, "st,stih416-hdmi")) {
                 res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
@@ -725,8 +725,8 @@ static int sti_hdmi_probe(struct platform_device *pdev)
                 }
                 hdmi->syscfg = devm_ioremap_nocache(dev, res->start,
                                                     resource_size(res));
-                if (IS_ERR(hdmi->syscfg))
-                        return PTR_ERR(hdmi->syscfg);
+                if (!hdmi->syscfg)
+                        return -ENOMEM;
 
         }
 
diff --git a/drivers/gpu/drm/sti/sti_tvout.c b/drivers/gpu/drm/sti/sti_tvout.c
index b69e26fee76e..b8afe490356a 100644
--- a/drivers/gpu/drm/sti/sti_tvout.c
+++ b/drivers/gpu/drm/sti/sti_tvout.c
@@ -591,8 +591,8 @@ static int sti_tvout_probe(struct platform_device *pdev)
                 return -ENOMEM;
         }
         tvout->regs = devm_ioremap_nocache(dev, res->start, resource_size(res));
-        if (IS_ERR(tvout->regs))
-                return PTR_ERR(tvout->regs);
+        if (!tvout->regs)
+                return -ENOMEM;
 
         /* get reset resources */
         tvout->reset = devm_reset_control_get(dev, "tvout");
@@ -624,7 +624,7 @@ static int sti_tvout_remove(struct platform_device *pdev)
         return 0;
 }
 
-static struct of_device_id tvout_of_match[] = {
+static const struct of_device_id tvout_of_match[] = {
         { .compatible = "st,stih416-tvout", },
         { .compatible = "st,stih407-tvout", },
         { /* end node */ }
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 07c28323f88f..1b233fc67466 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -892,6 +892,10 @@ config DEBUG_WW_MUTEX_SLOWPATH
          the full mutex checks enabled with (CONFIG_PROVE_LOCKING) this
          will test all possible w/w mutex interface abuse with the
          exception of simply not acquiring all the required locks.
+         Note that this feature can introduce significant overhead, so
+         it really should not be enabled in a production or distro kernel,
+         even a debug kernel.  If you are a driver writer, enable it.  If
+         you are a distro, do not.
 
 config DEBUG_LOCK_ALLOC
         bool "Lock debugging: detect incorrect freeing of live locks"