From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B683E5234; Sat, 4 May 2024 16:22:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714839766; cv=none; b=FUgYBVCEXFdYsrHPczbMv3+zUBqPZDSETYgDkD4nMrzt+NSolpqdDFhDQX9sH/mygz90rncPapFq+z5b1axXpGfSPtEXj+Uu9qDvt/bjJcpN5ZAaegMeIOsf9e573dPghSuxyJ3pdmvjpXdeqzxlsFZHW1gRHTD5kKuHnWIc53g= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714839766; c=relaxed/simple; bh=XLKwgizCMO/0zHsXGaNNz0G+hMai/8QuvXyzI6AcUqE=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=NuGDYre7JjdarNMmm5+C7M02kjitWta80L5+2ZAMfaxUr+gRlj6T93b+eJhIFxtZ+bLJwsT1nzaQiXtVAk371LV8IFk844XXAaAZas3qjEJbPz+atQjMgjJ6avuSexdDj4KCdBzh5DVVOPWKkYy3WrTTy2X8+ZSAJvDMUia3idM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=iDj5iatM; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="iDj5iatM" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 851EAC072AA; Sat, 4 May 2024 16:22:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1714839766; bh=XLKwgizCMO/0zHsXGaNNz0G+hMai/8QuvXyzI6AcUqE=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=iDj5iatMyaSz/gqhar/h1Hmk/M68eIoVvBF937rR/qRexhq3qW0e7IrOCv8oSRuAp RXcN2n3wxeDf6bXZn+6k4NXgbH2C+220eeWZDvoy8sSoLmjJvWpwz1iHSscnPVhyDV rqzw2pLlHDktLbaPfZGyoMeLs/VdR0Sczjt+Mb7I= Date: Sat, 4 May 2024 18:22:43 +0200 From: Greg Kroah-Hartman To: Dmitry Baryshkov Cc: Bryan O'Donoghue , Heikki Krogerus , Bjorn Andersson , Konrad Dybcio , Johan Hovold , linux-arm-msm@vger.kernel.org, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, Caleb Connolly Subject: Re: [PATCH v4] usb: typec: qcom-pmic-typec: split HPD bridge alloc and registration Message-ID: <2024050416-mandolin-gauging-9342@gregkh> References: <20240424-qc-pmic-typec-hpd-split-v4-1-f7e10d147443@linaro.org> <2024050415-retorted-gory-5fa6@gregkh> Precedence: bulk X-Mailing-List: linux-usb@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <2024050415-retorted-gory-5fa6@gregkh> On Sat, May 04, 2024 at 05:15:45PM +0200, Greg Kroah-Hartman wrote: > On Sat, May 04, 2024 at 05:23:20PM +0300, Dmitry Baryshkov wrote: > > On Wed, 24 Apr 2024 at 05:16, Dmitry Baryshkov > > wrote: > > > > > > If a probe function returns -EPROBE_DEFER after creating another device > > > there is a change of ending up in a probe deferral loop, (see commit > > > fbc35b45f9f6 ("Add documentation on meaning of -EPROBE_DEFER"). In case > > > of the qcom-pmic-typec driver the tcpm_register_port() function looks up > > > external resources (USB role switch and inherently via called > > > typec_register_port() USB-C muxes, switches and retimers). > > > > > > In order to prevent such probe-defer loops caused by qcom-pmic-typec > > > driver, use the API added by Johan Hovold and move HPD bridge > > > registration to the end of the probe function. > > > > > > The devm_drm_dp_hpd_bridge_add() is called at the end of the probe > > > function after all TCPM start functions. This is done as a way to > > > overcome a different problem, the DRM subsystem can not properly cope > > > with the DRM bridges being destroyed once the bridge is attached. Having > > > this function call at the end of the probe function prevents possible > > > DRM bridge device creation followed by destruction in case one of the > > > TCPM start functions returns an error. > > > > > > Reported-by: Caleb Connolly > > > Acked-by: Bryan O'Donoghue > > > Signed-off-by: Dmitry Baryshkov > > > --- > > > Dependency: https://lore.kernel.org/lkml/20240418145730.4605-2-johan+linaro@kernel.org/ > > > --- > > > Changes in v4: > > > - Rebased on top of Johan's patches > > > - Link to v3: https://lore.kernel.org/r/20240416-qc-pmic-typec-hpd-split-v3-1-fd071e3191a1@linaro.org > > > > > > Changes in v3: > > > - Updated commit message to explain my decisions (Johan). > > > - Link to v2: https://lore.kernel.org/r/20240408-qc-pmic-typec-hpd-split-v2-1-1704f5321b73@linaro.org > > > > > > Changes in v2: > > > - Fix commit message (Bryan) > > > - Link to v1: https://lore.kernel.org/r/20240405-qc-pmic-typec-hpd-split-v1-1-363daafb3c36@linaro.org > > > --- > > > drivers/usb/typec/tcpm/qcom/qcom_pmic_typec.c | 10 ++++++++-- > > > 1 file changed, 8 insertions(+), 2 deletions(-) > > > > A stupid gracious ping. It would be nice to fix the issue in 6.10 > > Is this a regression? If so, what commit does it fix? Or has it always > just not worked? Oh wait, I need Johan's patches applied first, I was waiting for that to happen, so I'll take this next week when that gets into Linus's tree, sorry for the delay. greg k-h