net: ipa: fix build-time bug in ipa_hardware_config_qsb()

Jon Hunter reported observing a build bug in the IPA driver:
  https://lore.kernel.org/netdev/5b5d9d40-94d5-5dad-b861-fd9bef8260e2@nvidia.com

The problem is that the QMB0 max read value set for IPA v4.5 (16) is
too large to fit in the 4-bit field.

The actual value we want is 0, which requests that the hardware use
the maximum it is capable of.

Reported-by: Jon Hunter <jonathanh@nvidia.com>
Tested-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Alex Elder <elder@linaro.org>
Link: https://lore.kernel.org/r/20201202141502.21265-1-elder@linaro.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/ipa/ipa_main.c b/drivers/net/ipa/ipa_main.c
index d076845..84bb8ae 100644 (file)
--- a/drivers/net/ipa/ipa_main.c
+++ b/drivers/net/ipa/ipa_main.c
@@ -288,7 +288,7 @@ static void ipa_hardware_config_qsb(struct ipa *ipa)
                max1 = 0;               /* PCIe not present */
                break;
        case IPA_VERSION_4_5:
-               max0 = 16;
+               max0 = 0;               /* No limit (hardware maximum) */
                break;
        }
        val = u32_encode_bits(max0, GEN_QMB_0_MAX_READS_FMASK);