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[78.88.45.245]) by smtp.gmail.com with ESMTPSA id a640c23a62f3a-b87023a8a33sm538070066b.18.2026.01.12.03.29.27 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 12 Jan 2026 03:29:29 -0800 (PST) Message-ID: <816456c5-ad32-4829-ae0d-a0d09f468863@oss.qualcomm.com> Date: Mon, 12 Jan 2026 12:29:26 +0100 Precedence: bulk X-Mailing-List: linux-pci@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 2/5] PCI: dwc: Add support for retaining link during host init To: Bjorn Helgaas , Krishna Chaitanya Chundru Cc: Vinod Koul , Neil Armstrong , Philipp Zabel , Jingoo Han , Manivannan Sadhasivam , Lorenzo Pieralisi , =?UTF-8?Q?Krzysztof_Wilczy=C5=84ski?= , Rob Herring , Bjorn Helgaas , linux-arm-msm@vger.kernel.org, linux-phy@lists.infradead.org, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org References: <20260109155350.GA546142@bhelgaas> Content-Language: en-US From: Konrad Dybcio In-Reply-To: <20260109155350.GA546142@bhelgaas> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Proofpoint-GUID: LpBvhNAB7AyITvcwVKKZgXtw0b3FGf3_ X-Proofpoint-ORIG-GUID: LpBvhNAB7AyITvcwVKKZgXtw0b3FGf3_ X-Proofpoint-Spam-Details-Enc: AW1haW4tMjYwMTEyMDA5MSBTYWx0ZWRfXzNiX+u21Z3pk giS8BCibuL9YgBVd/rrMfTn2cZaMvxK7eoYQDh44i/deg8xzJnH2IvIFCiaPrZLl9+55JXmDBKn I6sAmnhFRt0NEwwpGHEJqzC5/kPm2UOpqP4Vyw8sUtd9mN0sCUDWCnWvKhUPhu3C5ce8GOCX7jU a+FBUb7UH4Jwd2FW1FRNymQ4X/r5uEf+HgdJcD3B9YSzlPK32NpvVhlb2TzL1XHJfwsJYuigSOR 4gC6jgxTBaRLPJ4aH5HWGUcYWUXTnzjg5Lt4Un3N1I5di9+vLQdgHMt9Vlq7V2XgAZddKJfQ4Ls qCTt0JrsAd2M2XmO/cpM3BKM/mEEkN0FeekjnWp1RupUxL0m7gODJ2ARCvug2P6xwxsp4jMadMm D1hvSPcAAp7UhUc2omeftXNJtgXyV7nYC5HSHqSemZJdp2XoJMppqAfWu3CV/v9ZYC6oHsYvZen rV4AdaozO5iSe5yEkhQ== X-Authority-Analysis: v=2.4 cv=cs2WUl4i c=1 sm=1 tr=0 ts=6964db1b cx=c_pps a=mPf7EqFMSY9/WdsSgAYMbA==:117 a=FpWmc02/iXfjRdCD7H54yg==:17 a=IkcTkHD0fZMA:10 a=vUbySO9Y5rIA:10 a=s4-Qcg_JpJYA:10 a=VkNPw1HP01LnGYTKEx00:22 a=sQDjRcaqkbB8EtgPkRQA:9 a=QEXdDO2ut3YA:10 a=dawVfQjAaf238kedN5IG:22 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1121,Hydra:6.1.9,FMLib:17.12.100.49 definitions=2026-01-12_03,2026-01-09_02,2025-10-01_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 bulkscore=0 phishscore=0 spamscore=0 impostorscore=0 lowpriorityscore=0 malwarescore=0 priorityscore=1501 suspectscore=0 clxscore=1015 adultscore=0 classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.22.0-2512120000 definitions=main-2601120091 On 1/9/26 4:53 PM, Bjorn Helgaas wrote: > On Fri, Jan 09, 2026 at 12:51:07PM +0530, Krishna Chaitanya Chundru wrote: >> Some platforms keep the PCIe link up across bootloader and kernel >> handoff. In such cases, reinitializing the root complex is unnecessary >> if the DWC glue drivers wants to retain the PCIe link. >> >> Introduce a link_retain flag in struct dw_pcie_rp to indicate that >> the link should be preserved. When this flag is set by DWC glue drivers, >> skip dw_pcie_setup_rc() and only initialize MSI, avoiding redundant >> configuration steps. > > It sounds like this adds an assumption that the bootloader > initialization is the same as what dw_pcie_setup_rc() would do. This > assumption also applies to future changes in dw_pcie_setup_rc(). > > It looks like you mention an issue like this in [PATCH 4/5]; DBI & ATU > base being different than "HLOS" (whatever that is). This sounds like FYI, "HLOS" is a Qualcomm term for "High-Level OS".. which is a very pedantic way to say "OS" Konrad