From: Alex Deucher <alexander.deuc...@amd.com> If the bios or OS sets the pci max read request size to 0 or an invalid value (6,7), it can result in a hang or slowdown. Check and set it to something sane if it's invalid.
Fixes: https://bugzilla.kernel.org/show_bug.cgi?id=42162 v2: use pci reg defines from include/linux/pci_regs.h Signed-off-by: Alex Deucher <alexander.deucher at amd.com> Cc: stable at kernel.org --- drivers/gpu/drm/radeon/evergreen.c | 27 +++++++++++++++++++++++++++ drivers/gpu/drm/radeon/ni.c | 3 +++ 2 files changed, 30 insertions(+), 0 deletions(-) diff --git a/drivers/gpu/drm/radeon/evergreen.c b/drivers/gpu/drm/radeon/evergreen.c index d8b725d..cf5704f 100644 --- a/drivers/gpu/drm/radeon/evergreen.c +++ b/drivers/gpu/drm/radeon/evergreen.c @@ -41,6 +41,31 @@ static void evergreen_gpu_init(struct radeon_device *rdev); void evergreen_fini(struct radeon_device *rdev); static void evergreen_pcie_gen2_enable(struct radeon_device *rdev); +void evergreen_fix_pci_max_read_req_size(struct radeon_device *rdev) +{ + u16 ctl, v; + int cap, err; + + cap = pci_pcie_cap(rdev->pdev); + if (!cap) + return; + + err = pci_read_config_word(rdev->pdev, cap + PCI_EXP_DEVCTL, &ctl); + if (err) + return; + + v = (ctl & PCI_EXP_DEVCTL_READRQ) >> 12; + + /* if bios or OS sets MAX_READ_REQUEST_SIZE to an invalid value, fix it + * to avoid hangs or perfomance issues + */ + if ((v == 0) || (v == 6) || (v == 7)) { + ctl &= ~PCI_EXP_DEVCTL_READRQ; + ctl |= (2 << 12); + pci_write_config_word(rdev->pdev, cap + PCI_EXP_DEVCTL, ctl); + } +} + void evergreen_pre_page_flip(struct radeon_device *rdev, int crtc) { /* enable the pflip int */ @@ -1865,6 +1890,8 @@ static void evergreen_gpu_init(struct radeon_device *rdev) WREG32(GRBM_CNTL, GRBM_READ_TIMEOUT(0xff)); + evergreen_fix_pci_max_read_req_size(rdev); + cc_gc_shader_pipe_config = RREG32(CC_GC_SHADER_PIPE_CONFIG) & ~2; cc_gc_shader_pipe_config |= diff --git a/drivers/gpu/drm/radeon/ni.c b/drivers/gpu/drm/radeon/ni.c index d916c82..d6cb534 100644 --- a/drivers/gpu/drm/radeon/ni.c +++ b/drivers/gpu/drm/radeon/ni.c @@ -39,6 +39,7 @@ extern int evergreen_mc_wait_for_idle(struct radeon_device *rdev); extern void evergreen_mc_program(struct radeon_device *rdev); extern void evergreen_irq_suspend(struct radeon_device *rdev); extern int evergreen_mc_init(struct radeon_device *rdev); +extern void evergreen_fix_pci_max_read_req_size(struct radeon_device *rdev); #define EVERGREEN_PFP_UCODE_SIZE 1120 #define EVERGREEN_PM4_UCODE_SIZE 1376 @@ -724,6 +725,8 @@ static void cayman_gpu_init(struct radeon_device *rdev) WREG32(GRBM_CNTL, GRBM_READ_TIMEOUT(0xff)); + evergreen_fix_pci_max_read_req_size(rdev); + mc_shared_chmap = RREG32(MC_SHARED_CHMAP); mc_arb_ramcfg = RREG32(MC_ARB_RAMCFG); -- 1.7.1.1
