4.17-stable review patch. If anyone has any objections, please let me know.
------------------
From: Stephane Grosjean <s.grosjean@xxxxxxxxxxxxxxx>
commit 5d4c94ed9f564224d7b37dbee13f7c5d4a8a01ac upstream.
The DMA logic in firmwares < v3.3.0 embedded in the PCAN-PCIe FD cards
family is not capable of handling a mix of 32-bit and 64-bit logical
addresses. If the board is equipped with 2 or 4 CAN ports, then such a
situation might lead to a PCIe Bus Error "Malformed TLP" packet
as well as "irq xx: nobody cared" issue.
This patch adds a workaround that requests only 32-bit DMA addresses
when these might be allocated outside of the 4 GB area.
This issue has been fixed in firmware v3.3.0 and next.
Signed-off-by: Stephane Grosjean <s.grosjean@xxxxxxxxxxxxxxx>
Cc: linux-stable <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/net/can/peak_canfd/peak_pciefd_main.c | 19 +++++++++++++++++++
1 file changed, 19 insertions(+)
--- a/drivers/net/can/peak_canfd/peak_pciefd_main.c
+++ b/drivers/net/can/peak_canfd/peak_pciefd_main.c
@@ -58,6 +58,10 @@ MODULE_LICENSE("GPL v2");
#define PCIEFD_REG_SYS_VER1 0x0040 /* version reg #1 */
#define PCIEFD_REG_SYS_VER2 0x0044 /* version reg #2 */
+#define PCIEFD_FW_VERSION(x, y, z) (((u32)(x) << 24) | \
+ ((u32)(y) << 16) | \
+ ((u32)(z) << 8))
+
/* System Control Registers Bits */
#define PCIEFD_SYS_CTL_TS_RST 0x00000001 /* timestamp clock */
#define PCIEFD_SYS_CTL_CLK_EN 0x00000002 /* system clock */
@@ -783,6 +787,21 @@ static int peak_pciefd_probe(struct pci_
"%ux CAN-FD PCAN-PCIe FPGA v%u.%u.%u:\n", can_count,
hw_ver_major, hw_ver_minor, hw_ver_sub);
+#ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
+ /* FW < v3.3.0 DMA logic doesn't handle correctly the mix of 32-bit and
+ * 64-bit logical addresses: this workaround forces usage of 32-bit
+ * DMA addresses only when such a fw is detected.
+ */
+ if (PCIEFD_FW_VERSION(hw_ver_major, hw_ver_minor, hw_ver_sub) <
+ PCIEFD_FW_VERSION(3, 3, 0)) {
+ err = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
+ if (err)
+ dev_warn(&pdev->dev,
+ "warning: can't set DMA mask %llxh (err %d)\n",
+ DMA_BIT_MASK(32), err);
+ }
+#endif
+
/* stop system clock */
pciefd_sys_writereg(pciefd, PCIEFD_SYS_CTL_CLK_EN,
PCIEFD_REG_SYS_CTL_CLR);
