diff mbox series

[1/2] drm: replace incorrect Compliance/Margin magic numbers with PCI_EXP_LNKCTL2 definitions

Message ID 20191111192932.36048-2-helgaas@kernel.org
State Not Applicable
Headers show
Series drm: replace magic numbers | expand

Commit Message

Bjorn Helgaas Nov. 11, 2019, 7:29 p.m. UTC 
From: Bjorn Helgaas <bhelgaas@google.com>

Add definitions for these PCIe Link Control 2 register fields:

  Enter Compliance
  Transmit Margin

and use them in amdgpu and radeon.

NOTE: This is a functional change because "7 << 9" was apparently a typo.
That mask included the high order bit of Transmit Margin, the Enter
Modified Compliance bit, and the Compliance SOS bit, but I think what
was intended was the 3-bit Transmit Margin field at bits 9:7.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
---
 drivers/gpu/drm/amd/amdgpu/cik.c | 14 ++++++++++----
 drivers/gpu/drm/amd/amdgpu/si.c  | 10 +++++++---
 drivers/gpu/drm/radeon/cik.c     | 14 ++++++++++----
 drivers/gpu/drm/radeon/si.c      | 14 ++++++++++----
 include/uapi/linux/pci_regs.h    |  2 ++
 5 files changed, 39 insertions(+), 15 deletions(-)

Comments

Michel Dänzer Nov. 12, 2019, 4:45 p.m. UTC | #1 
On 2019-11-11 8:29 p.m., Bjorn Helgaas wrote:
> From: Bjorn Helgaas <bhelgaas@google.com>
> 
> Add definitions for these PCIe Link Control 2 register fields:
> 
>   Enter Compliance
>   Transmit Margin
> 
> and use them in amdgpu and radeon.
> 
> NOTE: This is a functional change because "7 << 9" was apparently a typo.
> That mask included the high order bit of Transmit Margin, the Enter
> Modified Compliance bit, and the Compliance SOS bit, but I think what
> was intended was the 3-bit Transmit Margin field at bits 9:7.

Can you split out the functional change into a separate patch 1? That
could make things easier for anyone who bisects the functional change
for whatever reason.
Bjorn Helgaas Nov. 12, 2019, 5:19 p.m. UTC | #2 
On Tue, Nov 12, 2019 at 05:45:15PM +0100, Michel Dänzer wrote:
> On 2019-11-11 8:29 p.m., Bjorn Helgaas wrote:
> > From: Bjorn Helgaas <bhelgaas@google.com>
> > 
> > Add definitions for these PCIe Link Control 2 register fields:
> > 
> >   Enter Compliance
> >   Transmit Margin
> > 
> > and use them in amdgpu and radeon.
> > 
> > NOTE: This is a functional change because "7 << 9" was apparently a typo.
> > That mask included the high order bit of Transmit Margin, the Enter
> > Modified Compliance bit, and the Compliance SOS bit, but I think what
> > was intended was the 3-bit Transmit Margin field at bits 9:7.
> 
> Can you split out the functional change into a separate patch 1? That
> could make things easier for anyone who bisects the functional change
> for whatever reason.

Great idea, thanks!  Wish I'd thought of that.

While fixing that, I also noticed I missed one case in
amdgpu/si.c.  I'll post a v3.
diff mbox series

Patch

diff --git a/drivers/gpu/drm/amd/amdgpu/cik.c b/drivers/gpu/drm/amd/amdgpu/cik.c
index b81bb414fcb3..e4a595cdd4c1 100644
--- a/drivers/gpu/drm/amd/amdgpu/cik.c
+++ b/drivers/gpu/drm/amd/amdgpu/cik.c
@@ -1498,13 +1498,19 @@  static void cik_pcie_gen3_enable(struct amdgpu_device *adev)
 
 				/* linkctl2 */
 				pci_read_config_word(root, bridge_pos + PCI_EXP_LNKCTL2, &tmp16);
-				tmp16 &= ~((1 << 4) | (7 << 9));
-				tmp16 |= (bridge_cfg2 & ((1 << 4) | (7 << 9)));
+				tmp16 &= ~(PCI_EXP_LNKCTL2_ENTER_COMP |
+					   PCI_EXP_LNKCTL2_TX_MARGIN);
+				tmp16 |= (bridge_cfg2 &
+					  (PCI_EXP_LNKCTL2_ENTER_COMP |
+					   PCI_EXP_LNKCTL2_TX_MARGIN));
 				pci_write_config_word(root, bridge_pos + PCI_EXP_LNKCTL2, tmp16);
 
 				pci_read_config_word(adev->pdev, gpu_pos + PCI_EXP_LNKCTL2, &tmp16);
-				tmp16 &= ~((1 << 4) | (7 << 9));
-				tmp16 |= (gpu_cfg2 & ((1 << 4) | (7 << 9)));
+				tmp16 &= ~(PCI_EXP_LNKCTL2_ENTER_COMP |
+					   PCI_EXP_LNKCTL2_TX_MARGIN);
+				tmp16 |= (gpu_cfg2 &
+					  (PCI_EXP_LNKCTL2_ENTER_COMP |
+					   PCI_EXP_LNKCTL2_TX_MARGIN));
 				pci_write_config_word(adev->pdev, gpu_pos + PCI_EXP_LNKCTL2, tmp16);
 
 				tmp = RREG32_PCIE(ixPCIE_LC_CNTL4);
diff --git a/drivers/gpu/drm/amd/amdgpu/si.c b/drivers/gpu/drm/amd/amdgpu/si.c
index 493af42152f2..cf543410a424 100644
--- a/drivers/gpu/drm/amd/amdgpu/si.c
+++ b/drivers/gpu/drm/amd/amdgpu/si.c
@@ -1737,12 +1737,16 @@  static void si_pcie_gen3_enable(struct amdgpu_device *adev)
 				pci_write_config_word(adev->pdev, gpu_pos + PCI_EXP_LNKCTL, tmp16);
 
 				pci_read_config_word(root, bridge_pos + PCI_EXP_LNKCTL2, &tmp16);
-				tmp16 &= ~((1 << 4) | (7 << 9));
-				tmp16 |= (bridge_cfg2 & ((1 << 4) | (7 << 9)));
+				tmp16 &= ~(PCI_EXP_LNKCTL2_ENTER_COMP |
+					   PCI_EXP_LNKCTL2_TX_MARGIN);
+				tmp16 |= (bridge_cfg2 &
+					  (PCI_EXP_LNKCTL2_ENTER_COMP |
+					   PCI_EXP_LNKCTL2_TX_MARGIN));
 				pci_write_config_word(root, bridge_pos + PCI_EXP_LNKCTL2, tmp16);
 
 				pci_read_config_word(adev->pdev, gpu_pos + PCI_EXP_LNKCTL2, &tmp16);
-				tmp16 &= ~((1 << 4) | (7 << 9));
+				tmp16 &= ~(PCI_EXP_LNKCTL2_ENTER_COMP |
+					   PCI_EXP_LNKCTL2_TX_MARGIN);
 				tmp16 |= (gpu_cfg2 & ((1 << 4) | (7 << 9)));
 				pci_write_config_word(adev->pdev, gpu_pos + PCI_EXP_LNKCTL2, tmp16);
 
diff --git a/drivers/gpu/drm/radeon/cik.c b/drivers/gpu/drm/radeon/cik.c
index 62eab82a64f9..95ffa0bff2d8 100644
--- a/drivers/gpu/drm/radeon/cik.c
+++ b/drivers/gpu/drm/radeon/cik.c
@@ -9619,13 +9619,19 @@  static void cik_pcie_gen3_enable(struct radeon_device *rdev)
 
 				/* linkctl2 */
 				pci_read_config_word(root, bridge_pos + PCI_EXP_LNKCTL2, &tmp16);
-				tmp16 &= ~((1 << 4) | (7 << 9));
-				tmp16 |= (bridge_cfg2 & ((1 << 4) | (7 << 9)));
+				tmp16 &= ~(PCI_EXP_LNKCTL2_ENTER_COMP |
+					   PCI_EXP_LNKCTL2_TX_MARGIN);
+				tmp16 |= (bridge_cfg2 &
+					  (PCI_EXP_LNKCTL2_ENTER_COMP |
+					   PCI_EXP_LNKCTL2_TX_MARGIN));
 				pci_write_config_word(root, bridge_pos + PCI_EXP_LNKCTL2, tmp16);
 
 				pci_read_config_word(rdev->pdev, gpu_pos + PCI_EXP_LNKCTL2, &tmp16);
-				tmp16 &= ~((1 << 4) | (7 << 9));
-				tmp16 |= (gpu_cfg2 & ((1 << 4) | (7 << 9)));
+				tmp16 &= ~(PCI_EXP_LNKCTL2_ENTER_COMP |
+					   PCI_EXP_LNKCTL2_TX_MARGIN);
+				tmp16 |= (gpu_cfg2 &
+					  (PCI_EXP_LNKCTL2_ENTER_COMP |
+					   PCI_EXP_LNKCTL2_TX_MARGIN));
 				pci_write_config_word(rdev->pdev, gpu_pos + PCI_EXP_LNKCTL2, tmp16);
 
 				tmp = RREG32_PCIE_PORT(PCIE_LC_CNTL4);
diff --git a/drivers/gpu/drm/radeon/si.c b/drivers/gpu/drm/radeon/si.c
index 05894d198a79..69993d34d1e9 100644
--- a/drivers/gpu/drm/radeon/si.c
+++ b/drivers/gpu/drm/radeon/si.c
@@ -7202,13 +7202,19 @@  static void si_pcie_gen3_enable(struct radeon_device *rdev)
 
 				/* linkctl2 */
 				pci_read_config_word(root, bridge_pos + PCI_EXP_LNKCTL2, &tmp16);
-				tmp16 &= ~((1 << 4) | (7 << 9));
-				tmp16 |= (bridge_cfg2 & ((1 << 4) | (7 << 9)));
+				tmp16 &= ~(PCI_EXP_LNKCTL2_ENTER_COMP |
+					   PCI_EXP_LNKCTL2_TX_MARGIN);
+				tmp16 |= (bridge_cfg2 &
+					  (PCI_EXP_LNKCTL2_ENTER_COMP |
+					   PCI_EXP_LNKCTL2_TX_MARGIN));
 				pci_write_config_word(root, bridge_pos + PCI_EXP_LNKCTL2, tmp16);
 
 				pci_read_config_word(rdev->pdev, gpu_pos + PCI_EXP_LNKCTL2, &tmp16);
-				tmp16 &= ~((1 << 4) | (7 << 9));
-				tmp16 |= (gpu_cfg2 & ((1 << 4) | (7 << 9)));
+				tmp16 &= ~(PCI_EXP_LNKCTL2_ENTER_COMP |
+					   PCI_EXP_LNKCTL2_TX_MARGIN);
+				tmp16 |= (gpu_cfg2 &
+					  (PCI_EXP_LNKCTL2_ENTER_COMP |
+					   PCI_EXP_LNKCTL2_TX_MARGIN));
 				pci_write_config_word(rdev->pdev, gpu_pos + PCI_EXP_LNKCTL2, tmp16);
 
 				tmp = RREG32_PCIE_PORT(PCIE_LC_CNTL4);
diff --git a/include/uapi/linux/pci_regs.h b/include/uapi/linux/pci_regs.h
index 29d6e93fd15e..5869e5778a05 100644
--- a/include/uapi/linux/pci_regs.h
+++ b/include/uapi/linux/pci_regs.h
@@ -673,6 +673,8 @@ 
 #define  PCI_EXP_LNKCTL2_TLS_8_0GT	0x0003 /* Supported Speed 8GT/s */
 #define  PCI_EXP_LNKCTL2_TLS_16_0GT	0x0004 /* Supported Speed 16GT/s */
 #define  PCI_EXP_LNKCTL2_TLS_32_0GT	0x0005 /* Supported Speed 32GT/s */
+#define  PCI_EXP_LNKCTL2_ENTER_COMP	0x0010 /* Enter Compliance */
+#define  PCI_EXP_LNKCTL2_TX_MARGIN	0x0380 /* Transmit Margin */
 #define PCI_EXP_LNKSTA2		50	/* Link Status 2 */
 #define PCI_CAP_EXP_ENDPOINT_SIZEOF_V2	52	/* v2 endpoints with link end here */
 #define PCI_EXP_SLTCAP2		52	/* Slot Capabilities 2 */