Messages in this thread | | | Subject | Re: [PATCH 5.10 14/49] net: ipa: ignore CHANNEL_NOT_RUNNING errors | From | Alex Elder <> | Date | Wed, 10 Mar 2021 11:48:03 -0600 |
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On 3/10/21 11:36 AM, 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 ]
Upstream commit f849afcc8c3b27d7b5 is described as: v5.10-rc4-1094-gf849afcc8c3b2 Is this being "back-ported" to v5.10 stable?
Maybe I'm confused.
-Alex
>> 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/1086862412#L210 >
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