linux-kernel - Re: [PATCH v3 0/3] phy: qcom: edp: Add missing ref clock to x1e80100

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [day] [month] [year] [list]
Message-ID: <aM1wnAw0mA-iNgJy@linaro.org>
Date: Fri, 19 Sep 2025 17:02:52 +0200
From: Stephan Gerhold <stephan.gerhold@...aro.org>
To: Xilin Wu <sophon@...xa.com>
Cc: Abel Vesa <abel.vesa@...aro.org>, Vinod Koul <vkoul@...nel.org>,
	Kishon Vijay Abraham I <kishon@...nel.org>,
	Rob Herring <robh@...nel.org>,
	Krzysztof Kozlowski <krzk+dt@...nel.org>,
	Conor Dooley <conor+dt@...nel.org>,
	Bjorn Andersson <andersson@...nel.org>,
	Dmitry Baryshkov <lumag@...nel.org>,
	Konrad Dybcio <konradybcio@...nel.org>,
	Sibi Sankar <quic_sibis@...cinc.com>,
	Rajendra Nayak <quic_rjendra@...cinc.com>,
	Johan Hovold <johan@...nel.org>, Taniya Das <quic_tdas@...cinc.com>,
	Krzysztof Kozlowski <krzysztof.kozlowski@...aro.org>,
	linux-arm-msm@...r.kernel.org, linux-phy@...ts.infradead.org,
	devicetree@...r.kernel.org, linux-kernel@...r.kernel.org,
	stable@...r.kernel.org
Subject: Re: [PATCH v3 0/3] phy: qcom: edp: Add missing ref clock to x1e80100

On Fri, Sep 19, 2025 at 07:06:36PM +0800, Xilin Wu wrote:
> On 9/9/2025 3:33 PM, Abel Vesa wrote:
> > According to documentation, the DP PHY on x1e80100 has another clock
> > called ref.
> > 
> > The current X Elite devices supported upstream work fine without this
> > clock, because the boot firmware leaves this clock enabled. But we should
> > not rely on that. Also, when it comes to power management, this clock
> > needs to be also disabled on suspend. So even though this change breaks
> > the ABI, it is needed in order to make we disable this clock on runtime
> > PM, when that is going to be enabled in the driver.
> > 
> > So rework the driver to allow different number of clocks, fix the
> > dt-bindings schema and add the clock to the DT node as well.
> > 
> > Signed-off-by: Abel Vesa <abel.vesa@...aro.org>
> > ---
> > Changes in v3:
> > - Use dev_err_probe() on clocks parsing failure.
> > - Explain why the ABI break is necessary.
> > - Drop the extra 'clk' suffix from the clock name. So ref instead of
> >    refclk.
> > - Link to v2: https://lore.kernel.org/r/20250903-phy-qcom-edp-add-missing-refclk-v2-0-d88c1b0cdc1b@linaro.org
> > 
> > Changes in v2:
> > - Fix schema by adding the minItems, as suggested by Krzysztof.
> > - Use devm_clk_bulk_get_all, as suggested by Konrad.
> > - Rephrase the commit messages to reflect the flexible number of clocks.
> > - Link to v1: https://lore.kernel.org/r/20250730-phy-qcom-edp-add-missing-refclk-v1-0-6f78afeadbcf@linaro.org
> > 
> > ---
> > Abel Vesa (3):
> >        dt-bindings: phy: qcom-edp: Add missing clock for X Elite
> >        phy: qcom: edp: Make the number of clocks flexible
> >        arm64: dts: qcom: Add missing TCSR ref clock to the DP PHYs
> > 
> >   .../devicetree/bindings/phy/qcom,edp-phy.yaml      | 28 +++++++++++++++++++++-
> >   arch/arm64/boot/dts/qcom/x1e80100.dtsi             | 12 ++++++----
> >   drivers/phy/qualcomm/phy-qcom-edp.c                | 16 ++++++-------
> >   3 files changed, 43 insertions(+), 13 deletions(-)
> > ---
> > base-commit: 65dd046ef55861190ecde44c6d9fcde54b9fb77d
> > change-id: 20250730-phy-qcom-edp-add-missing-refclk-5ab82828f8e7
> > 
> > Best regards,
> 
> Hi,
> 
> I'm observing what looks like a related clock failure on sc8280xp when
> booting without a monitor connected to a DP-to-HDMI bridge on mdss0_dp2.
> 
> Do you think sc8280xp might require a similar fix, or could this be a
> different issue?
> 
> 
> [    0.390390] ------------[ cut here ]------------
> [    0.390398] disp0_cc_mdss_dptx2_link_clk_src: rcg didn't update its
> configuration.
> [    0.390419] WARNING: CPU: 0 PID: 63 at drivers/clk/qcom/clk-rcg2.c:136
> update_config+0xa4/0xb0
> [    0.390439] Modules linked in:
> [    0.390448] CPU: 0 UID: 0 PID: 63 Comm: kworker/u32:1 Not tainted 6.16.3+
> #45 PREEMPT(lazy)
> [    0.390455] Hardware name: Qualcomm QRD, BIOS
> 6.0.250905.BOOT.MXF.1.1.c1-00167-MAKENA-1 09/ 5/2025
> [    0.390460] Workqueue: events_unbound deferred_probe_work_func
> [    0.390476] pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS
> BTYPE=--)
> [    0.390482] pc : update_config+0xa4/0xb0
> [    0.390492] lr : update_config+0xa4/0xb0
> [    0.390500] sp : ffff80008351b9e0
> [    0.390504] x29: ffff80008351b9e0 x28: 0000000000000000 x27:
> ffff0000850ec3c0
> [    0.390515] x26: ffff800081205320 x25: 0000000000000002 x24:
> 0000000000000000
> [    0.390523] x23: ffff8000812052a0 x22: ffff000080467800 x21:
> ffff800081207ef0
> [    0.390531] x20: ffff8000822ad6f0 x19: 0000000000000000 x18:
> ffffffffffc06b68
> [    0.390539] x17: 616c707369642e30 x16: 3030313065613a6d x15:
> ffff800081474230
> [    0.390547] x14: ffffffffff806b67 x13: 2e6e6f6974617275 x12:
> 6769666e6f632073
> [    0.390556] x11: 0000000000000058 x10: 0000000000000018 x9 :
> ffff8000814742b8
> [    0.390565] x8 : 0000000000afffa8 x7 : 0000000000000179 x6 :
> ffff800081f742b8
> [    0.390574] x5 : ffff800081f742b8 x4 : 0000000000000178 x3 :
> 00000000fffdffff
> [    0.390582] x2 : ffff8000814741f8 x1 : ffff00008091cec0 x0 :
> 0000000100000000
> [    0.390591] Call trace:
> [    0.390595]  update_config+0xa4/0xb0 (P)
> [    0.390606]  clk_rcg2_set_parent+0x58/0x68
> [    0.390617]  clk_core_set_parent_nolock+0xc4/0x1e0
> [    0.390630]  clk_set_parent+0x40/0x144
> [    0.390638]  of_clk_set_defaults+0x12c/0x520
> [    0.390645]  platform_probe+0x38/0xdc
> [    0.390652]  really_probe+0xc0/0x390
> [    0.390657]  __driver_probe_device+0x7c/0x150
> [    0.390663]  driver_probe_device+0x40/0x120
> [    0.390667]  __device_attach_driver+0xbc/0x168
> [    0.390673]  bus_for_each_drv+0x74/0xc0
> [    0.390684]  __device_attach+0x9c/0x1ac
> [    0.390688]  device_initial_probe+0x14/0x20
> [    0.390694]  bus_probe_device+0x9c/0xa0
> [    0.390703]  deferred_probe_work_func+0xa8/0xf8
> [    0.390713]  process_one_work+0x150/0x2b0
> [    0.390725]  worker_thread+0x2d0/0x3ec
> [    0.390731]  kthread+0x118/0x1e0
> [    0.390738]  ret_from_fork+0x10/0x20
> [    0.390751] ---[ end trace 0000000000000000 ]---
> [    0.390760] clk: failed to reparent disp0_cc_mdss_dptx2_link_clk_src to
> aec2a00.phy::link_clk: -16
> [    0.401093] ------------[ cut here ]------------
> [    0.401096] disp0_cc_mdss_dptx2_pixel0_clk_src: rcg didn't update its
> configuration.
> [    0.401112] WARNING: CPU: 0 PID: 63 at drivers/clk/qcom/clk-rcg2.c:136
> update_config+0xa4/0xb0
> [    0.401126] Modules linked in:
> [    0.401132] CPU: 0 UID: 0 PID: 63 Comm: kworker/u32:1 Tainted: G   W
> 6.16.3+ #45 PREEMPT(lazy)
> [    0.401141] Tainted: [W]=WARN
> [    0.401144] Hardware name: Qualcomm QRD, BIOS
> 6.0.250905.BOOT.MXF.1.1.c1-00167-MAKENA-1 09/ 5/2025
> [    0.401147] Workqueue: events_unbound deferred_probe_work_func
> [    0.401159] pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS
> BTYPE=--)
> [    0.401164] pc : update_config+0xa4/0xb0
> [    0.401174] lr : update_config+0xa4/0xb0
> [    0.401182] sp : ffff80008351b9e0
> [    0.401185] x29: ffff80008351b9e0 x28: 00000000fffffff0 x27:
> ffff0000850ec3c0
> [    0.401194] x26: ffff800081205320 x25: 0000000000000002 x24:
> 0000000000000000
> [    0.401203] x23: ffff8000812052a0 x22: ffff000080467800 x21:
> ffff800081207ea0
> [    0.401211] x20: ffff8000822ad640 x19: 0000000000000000 x18:
> ffffffffffc07528
> [    0.401219] x17: 32636561206f7420 x16: 0001020ef3c08cb3 x15:
> ffff800081474230
> [    0.401227] x14: ffffffffff807527 x13: 2e6e6f6974617275 x12:
> 6769666e6f632073
> [    0.401235] x11: 0000000000000058 x10: 0000000000000018 x9 :
> ffff8000814742b8
> [    0.401243] x8 : 0000000000afffa8 x7 : 00000000000001a4 x6 :
> ffff800081f742b8
> [    0.401252] x5 : ffff800081f742b8 x4 : 00000000000001a3 x3 :
> 00000000fffdffff
> [    0.401260] x2 : ffff8000814741f8 x1 : ffff00008091cec0 x0 :
> 0000000100000000
> [    0.401268] Call trace:
> [    0.401271]  update_config+0xa4/0xb0 (P)
> [    0.401281]  clk_rcg2_set_parent+0x58/0x68
> [    0.401291]  clk_core_set_parent_nolock+0xc4/0x1e0
> [    0.401299]  clk_set_parent+0x40/0x144
> [    0.401308]  of_clk_set_defaults+0x12c/0x520
> [    0.401314]  platform_probe+0x38/0xdc
> [    0.401321]  really_probe+0xc0/0x390
> [    0.401325]  __driver_probe_device+0x7c/0x150
> [    0.401330]  driver_probe_device+0x40/0x120
> [    0.401335]  __device_attach_driver+0xbc/0x168
> [    0.401340]  bus_for_each_drv+0x74/0xc0
> [    0.401349]  __device_attach+0x9c/0x1ac
> [    0.401353]  device_initial_probe+0x14/0x20
> [    0.401358]  bus_probe_device+0x9c/0xa0
> [    0.401367]  deferred_probe_work_func+0xa8/0xf8
> [    0.401377]  process_one_work+0x150/0x2b0
> [    0.401384]  worker_thread+0x2d0/0x3ec
> [    0.401390]  kthread+0x118/0x1e0
> [    0.401395]  ret_from_fork+0x10/0x20
> [    0.401405] ---[ end trace 0000000000000000 ]---
> [    0.401412] clk: failed to reparent disp0_cc_mdss_dptx2_pixel0_clk_src to
> aec2a00.phy::vco_div_clk: -16
> 

The same happens on the X1E Devkit if there is nothing connected to the
HDMI port. I believe you are looking for my patch series instead. :-)

https://lore.kernel.org/r/20250814-platform-delay-clk-defaults-v1-0-4aae5b33512f@linaro.org/T/

If it works for you, replying with a Tested-by there would be much
appreciated. I'm still trying to convince folks that the approach of the
series is the best way to move forward with this issue. :-)

Thanks,
Stephan