diff options
| author | Jeffrey Hugo <quic_jhugo@quicinc.com> | 2023-12-08 09:31:01 -0700 |
|---|---|---|
| committer | Jeffrey Hugo <quic_jhugo@quicinc.com> | 2023-12-15 10:40:37 -0700 |
| commit | 4c8874c2a6512b9fe7285cab1a6910d9211a6cfb (patch) | |
| tree | 8b003283522ed54068cd49e002e2c8b5dfb2fb91 /drivers/accel | |
| parent | c8b6f4ad2ff9c6d88cdeb9acf16d0c4a323dd499 (diff) | |
accel/qaic: Implement quirk for SOC_HW_VERSION
The SOC_HW_VERSION register in the BHI space is not correctly initialized
by the device and in many cases contains uninitialized data. The register
could contain 0xFFFFFFFF which is a special value to indicate a link
error in PCIe, therefore if observed, we could incorrectly think the
device is down.
Intercept reads for this register, and provide the correct value - every
production instance would read 0x60110200 if the device was operating as
intended.
Fixes: a36bf7af868b ("accel/qaic: Add MHI controller")
Signed-off-by: Jeffrey Hugo <quic_jhugo@quicinc.com>
Reviewed-by: Pranjal Ramajor Asha Kanojiya <quic_pkanojiy@quicinc.com>
Reviewed-by: Jacek Lawrynowicz <jacek.lawrynowicz@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231208163101.1295769-3-quic_jhugo@quicinc.com
Diffstat (limited to 'drivers/accel')
| -rw-r--r-- | drivers/accel/qaic/mhi_controller.c | 15 |
1 files changed, 14 insertions, 1 deletions
diff --git a/drivers/accel/qaic/mhi_controller.c b/drivers/accel/qaic/mhi_controller.c index 5036e58e7235..1405623b03e4 100644 --- a/drivers/accel/qaic/mhi_controller.c +++ b/drivers/accel/qaic/mhi_controller.c @@ -404,8 +404,21 @@ static struct mhi_controller_config aic100_config = { static int mhi_read_reg(struct mhi_controller *mhi_cntrl, void __iomem *addr, u32 *out) { - u32 tmp = readl_relaxed(addr); + u32 tmp; + /* + * SOC_HW_VERSION quirk + * The SOC_HW_VERSION register (offset 0x224) is not reliable and + * may contain uninitialized values, including 0xFFFFFFFF. This could + * cause a false positive link down error. Instead, intercept any + * reads and provide the correct value of the register. + */ + if (addr - mhi_cntrl->regs == 0x224) { + *out = 0x60110200; + return 0; + } + + tmp = readl_relaxed(addr); if (tmp == U32_MAX) return -EIO; |