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path: root/drivers/gpu/drm/msm/dp/dp_aux.c
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2021-11-22drm/msm/dp: Avoid unpowered AUX xfers that caused crashesDouglas Anderson
If you happened to try to access `/dev/drm_dp_aux` devices provided by the MSM DP AUX driver too early at bootup you could go boom. Let's avoid that by only allowing AUX transfers when the controller is powered up. Specifically the crash that was seen (on Chrome OS 5.4 tree with relevant backports): Kernel panic - not syncing: Asynchronous SError Interrupt CPU: 0 PID: 3131 Comm: fwupd Not tainted 5.4.144-16620-g28af11b73efb #1 Hardware name: Google Lazor (rev3+) with KB Backlight (DT) Call trace: dump_backtrace+0x0/0x14c show_stack+0x20/0x2c dump_stack+0xac/0x124 panic+0x150/0x390 nmi_panic+0x80/0x94 arm64_serror_panic+0x78/0x84 do_serror+0x0/0x118 do_serror+0xa4/0x118 el1_error+0xbc/0x160 dp_catalog_aux_write_data+0x1c/0x3c dp_aux_cmd_fifo_tx+0xf0/0x1b0 dp_aux_transfer+0x1b0/0x2bc drm_dp_dpcd_access+0x8c/0x11c drm_dp_dpcd_read+0x64/0x10c auxdev_read_iter+0xd4/0x1c4 I did a little bit of tracing and found that: * We register the AUX device very early at bootup. * Power isn't actually turned on for my system until hpd_event_thread() -> dp_display_host_init() -> dp_power_init() * You can see that dp_power_init() calls dp_aux_init() which is where we start allowing AUX channel requests to go through. In general this patch is a bit of a bandaid but at least it gets us out of the current state where userspace acting at the wrong time can fully crash the system. * I think the more proper fix (which requires quite a bit more changes) is to power stuff on while an AUX transfer is happening. This is like the solution we did for ti-sn65dsi86. This might be required for us to move to populating the panel via the DP-AUX bus. * Another fix considered was to dynamically register / unregister. I tried that at <https://crrev.com/c/3169431/3> but it got ugly. Currently there's a bug where the pm_runtime() state isn't tracked properly and that causes us to just keep registering more and more. Signed-off-by: Douglas Anderson <dianders@chromium.org> Reviewed-by: Kuogee Hsieh <quic_khsieh@quicinc.com> Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com> Link: https://lore.kernel.org/r/20211109100403.1.I4e23470d681f7efe37e2e7f1a6466e15e9bb1d72@changeid Signed-off-by: Rob Clark <robdclark@chromium.org>
2021-08-10drm/msm/dp: reset aux controller after dp_aux_cmd_fifo_tx() failed.Kuogee Hsieh
Aux hardware calibration sequence requires resetting the aux controller in order for the new setting to take effect. However resetting the AUX controller will also clear HPD interrupt status which may accidentally cause pending unplug interrupt to get lost. Therefore reset aux controller only when link is in connection state when dp_aux_cmd_fifo_tx() fail. This fixes Link Layer CTS cases 4.2.1.1 and 4.2.1.2. Signed-off-by: Kuogee Hsieh <khsieh@codeaurora.org> Reviewed-by: Stephen Boyd <swboyd@chromium.org> Link: https://lore.kernel.org/r/1628196295-7382-4-git-send-email-khsieh@codeaurora.org Signed-off-by: Rob Clark <robdclark@chromium.org>
2021-06-23drm/msm/dp: Handle aux timeouts, nacks, defersStephen Boyd
Let's look at the irq status bits after a transfer and see if we got a nack or a defer or a timeout, instead of telling drm layers that everything was fine, while still printing an error message. I wasn't sure about NACK+DEFER so I lumped all those various errors along with a nack so that the drm core can figure out that things are just not going well. The important thing is that we're now returning -ETIMEDOUT when the message times out and nacks for bad addresses. Cc: Dmitry Baryshkov <dmitry.baryshkov@linaro.org> Cc: Abhinav Kumar <abhinavk@codeaurora.org> Cc: Kuogee Hsieh <khsieh@codeaurora.org> Cc: aravindh@codeaurora.org Cc: Sean Paul <sean@poorly.run> Signed-off-by: Stephen Boyd <swboyd@chromium.org> Reviewed-by: Kuogee Hsieh <khsieh@codeaurora.org> Link: https://lore.kernel.org/r/20210507212505.1224111-4-swboyd@chromium.org Signed-off-by: Rob Clark <robdclark@chromium.org>
2021-06-23drm/msm/dp: Shrink locking area of dp_aux_transfer()Stephen Boyd
We don't need to hold the lock to inspect the message we're going to transfer, and we don't need to clear the busy flag either. Take the lock later and bail out earlier if conditions aren't met. Cc: Dmitry Baryshkov <dmitry.baryshkov@linaro.org> Cc: Abhinav Kumar <abhinavk@codeaurora.org> Cc: Kuogee Hsieh <khsieh@codeaurora.org> Cc: aravindh@codeaurora.org Cc: Sean Paul <sean@poorly.run> Signed-off-by: Stephen Boyd <swboyd@chromium.org> Reviewed-by: Kuogee Hsieh <khsieh@codeaurora.org> Link: https://lore.kernel.org/r/20210507212505.1224111-3-swboyd@chromium.org Signed-off-by: Rob Clark <robdclark@chromium.org>
2021-06-23drm/msm/dp: Simplify aux irq handling codeStephen Boyd
We don't need to stash away 'isr' in the aux structure to pass to two functions. Let's use a local variable instead. And we can complete the completion variable in one place instead of two to simplify the code. Cc: Dmitry Baryshkov <dmitry.baryshkov@linaro.org> Cc: Abhinav Kumar <abhinavk@codeaurora.org> Cc: Kuogee Hsieh <khsieh@codeaurora.org> Cc: aravindh@codeaurora.org Cc: Sean Paul <sean@poorly.run> Signed-off-by: Stephen Boyd <swboyd@chromium.org> Reviewed-by: Kuogee Hsieh <khsieh@codeaurora.org> Link: https://lore.kernel.org/r/20210507212505.1224111-2-swboyd@chromium.org Signed-off-by: Rob Clark <robdclark@chromium.org>
2021-03-17drm/msm/dp: Restore aux retry tuning logicStephen Boyd
In commit 9fc418430c65 ("drm/msm/dp: unplug interrupt missed after irq_hpd handler") we dropped a reset of the aux phy during aux transfers because resetting the phy during active communication caused us to miss an hpd irq in some cases. Unfortunately, we also dropped the part of the code that changes the aux phy tuning when an aux transfer fails due to a timeout. That part of the code was calling into the phy driver to reconfigure the aux TX swing controls, working around poor channel quality. Let's restore this phy setting code so that aux channel communication is more reliable. Cc: Kuogee Hsieh <khsieh@codeaurora.org> Fixes: 9fc418430c65 ("drm/msm/dp: unplug interrupt missed after irq_hpd handler") Signed-off-by: Stephen Boyd <swboyd@chromium.org> Signed-off-by: Rob Clark <robdclark@chromium.org>
2021-01-31drm/msm/dp: unplug interrupt missed after irq_hpd handlerKuogee Hsieh
There is HPD unplug interrupts missed at scenario of an irq_hpd followed by unplug interrupts with around 10 ms in between. Since both AUX_SW_RESET and DP_SW_RESET clear pending HPD interrupts, irq_hpd handler should not issues either aux or sw reset to avoid following unplug interrupt be cleared accidentally. This patch also postpone handling of irq_hpd until connected state if it happened at connection pending state. Changes in V2: -- add postpone handling of irq_hpd until connected state -- check DP_TRAINING_1 instead of DP_TRAINING_NONE Signed-off-by: Kuogee Hsieh <khsieh@codeaurora.org> Signed-off-by: Rob Clark <robdclark@chromium.org>
2020-09-15drm/msm/dp: Use qmp phy for DP PLL and PHYStephen Boyd
Make the necessary changes to the DP driver to use the qmp phy from the common phy framework instead of rolling our own in the drm subsystem. This also removes the PLL code and adds proper includes so things build. Cc: Jeykumar Sankaran <jsanka@codeaurora.org> Cc: Chandan Uddaraju <chandanu@codeaurora.org> Cc: Vara Reddy <varar@codeaurora.org> Cc: Tanmay Shah <tanmay@codeaurora.org> Cc: Bjorn Andersson <bjorn.andersson@linaro.org> Cc: Manu Gautam <mgautam@codeaurora.org> Cc: Sandeep Maheswaram <sanm@codeaurora.org> Cc: Douglas Anderson <dianders@chromium.org> Cc: Sean Paul <seanpaul@chromium.org> Cc: Jonathan Marek <jonathan@marek.ca> Cc: Dmitry Baryshkov <dmitry.baryshkov@linaro.org> Cc: Rob Clark <robdclark@chromium.org> Signed-off-by: Stephen Boyd <swboyd@chromium.org> Signed-off-by: Rob Clark <robdclark@chromium.org>
2020-09-15drm/msm/dp: Add DP compliance tests on Snapdragon ChipsetsKuogee Hsieh
add event thread to execute events serially from event queue. Also timeout mode is supported which allow an event be deferred to be executed at later time. Both link and phy compliant tests had been done successfully. Changes in v2: -- Fix potential deadlock by removing redundant connect_mutex -- Check and enable link clock during modeset -- Drop unused code and fix function prototypes. -- set sink power to normal operation state (D0) before DPCD read Changes in v3: -- push idle pattern at main link before timing generator off -- add timeout handles for both connect and disconnect Changes in v4: -- add ST_SUSPEND_PENDING to handles suspend/modeset test operations -- clear dp phy aux interrupt status when ERR_DPPHY_AUX error -- send segment addr during edid read -- clear bpp depth before MISC register write Changes in v5: -- add ST_SUSPENDED to fix crash at resume Changes in v6: -- at msm_dp_display_enable() do not return until resume_done to avoid kms commit timeout Signed-off-by: Kuogee Hsieh <khsieh@codeaurora.org> Signed-off-by: Rob Clark <robdclark@chromium.org>
2020-09-15drm/msm/dp: add displayPort driver supportChandan Uddaraju
Add the needed displayPort files to enable DP driver on msm target. "dp_display" module is the main module that calls into other sub-modules. "dp_drm" file represents the interface between DRM framework and DP driver. Changes in v12: -- Add support of pm ops in display port driver -- Clear bpp depth bits before writing to MISC register -- Fix edid read Previous Change log: https://lkml.kernel.org/lkml/20200818051137.21478-3-tanmay@codeaurora.org/ Signed-off-by: Chandan Uddaraju <chandanu@codeaurora.org> Signed-off-by: Vara Reddy <varar@codeaurora.org> Signed-off-by: Tanmay Shah <tanmay@codeaurora.org> Co-developed-by: Abhinav Kumar <abhinavk@codeaurora.org> Signed-off-by: Abhinav Kumar <abhinavk@codeaurora.org> Co-developed-by: Kuogee Hsieh <khsieh@codeaurora.org> Signed-off-by: Kuogee Hsieh <khsieh@codeaurora.org> Co-developed-by: Guenter Roeck <groeck@chromium.org> Signed-off-by: Guenter Roeck <groeck@chromium.org> Co-developed-by: Stephen Boyd <swboyd@chromium.org> Signed-off-by: Stephen Boyd <swboyd@chromium.org> Signed-off-by: Rob Clark <robdclark@chromium.org>