On Wed, Mar 10, 2021 at 11:06:09PM +0530, Naresh Kamboju wrote:
On Wed, 10 Mar 2021 at 18:56, gregkh@linuxfoundation.org wrote:
From: Greg Kroah-Hartman gregkh@linuxfoundation.org
From: Alex Elder elder@linaro.org
[ Upstream commit f849afcc8c3b27d7b50827e95b60557f24184df0 ]
IPA v4.2 has a hardware quirk that requires the AP to allocate GSI channels for the modem to use. It is recommended that these modem channels get stopped (with a HALT generic command) by the AP when its IPA driver gets removed.
The AP has no way of knowing the current state of a modem channel. So when the IPA driver issues a HALT command it's possible the channel is not running, and in that case we get an error indication. This error simply means we didn't need to stop the channel, so we can ignore it.
This patch adds an explanation for this situation, and arranges for this condition to *not* report an error message.
Signed-off-by: Alex Elder elder@linaro.org Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org
drivers/net/ipa/gsi.c | 24 +++++++++++++++++++++++- 1 file changed, 23 insertions(+), 1 deletion(-)
diff --git a/drivers/net/ipa/gsi.c b/drivers/net/ipa/gsi.c index 2a65efd3e8da..48ee43b89fec 100644 --- a/drivers/net/ipa/gsi.c +++ b/drivers/net/ipa/gsi.c @@ -1052,10 +1052,32 @@ static void gsi_isr_gp_int1(struct gsi *gsi) u32 result; u32 val;
/* This interrupt is used to handle completions of the two GENERIC* GSI commands. We use these to allocate and halt channels on* the modem's behalf due to a hardware quirk on IPA v4.2. Once* allocated, the modem "owns" these channels, and as a result we* have no way of knowing the channel's state at any given time.** It is recommended that we halt the modem channels we allocated* when shutting down, but it's possible the channel isn't running* at the time we issue the HALT command. We'll get an error in* that case, but it's harmless (the channel is already halted).** For this reason, we silently ignore a CHANNEL_NOT_RUNNING error* if we receive it.*/ val = ioread32(gsi->virt + GSI_CNTXT_SCRATCH_0_OFFSET); result = u32_get_bits(val, GENERIC_EE_RESULT_FMASK);
if (result != GENERIC_EE_SUCCESS_FVAL)
switch (result) {case GENERIC_EE_SUCCESS_FVAL:case GENERIC_EE_CHANNEL_NOT_RUNNING_FVAL:While building stable rc 5.10 for arm64 the build failed due to the following errors / warnings.
make --silent --keep-going --jobs=8 O=/home/tuxbuild/.cache/tuxmake/builds/1/tmp ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- 'HOSTCC=sccache clang' 'CC=sccache clang' drivers/net/ipa/gsi.c:1074:7: error: use of undeclared identifier 'GENERIC_EE_CHANNEL_NOT_RUNNING_FVAL' case GENERIC_EE_CHANNEL_NOT_RUNNING_FVAL: ^ 1 error generated. make[4]: *** [scripts/Makefile.build:279: drivers/net/ipa/gsi.o] Error 1
Reported-by: Linux Kernel Functional Testing lkft@linaro.org
Build log link, https://gitlab.com/Linaro/lkft/mirrors/stable/linux-stable-rc/-/jobs/1086862...
I'll go drop this and push out a -rc2 now, thanks.
greg k-h