[PATCH v2 net-next] net: ipa: fix build-time bug in ipa_hardware_config_qsb()

From: Alex Elder
Date: Wed Dec 02 2020 - 09:15:47 EST


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

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@xxxxxxxxxx>
Tested-by: Jon Hunter <jonathanh@xxxxxxxxxx>
Signed-off-by: Alex Elder <elder@xxxxxxxxxx>
---
v2: Got confirmation that 0 is the desired value to use (with comment).

drivers/net/ipa/ipa_main.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ipa/ipa_main.c b/drivers/net/ipa/ipa_main.c
index d0768452c15cf..84bb8ae927252 100644
--- 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);
--
2.20.1