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charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: X-Proofpoint-Spam-Details-Enc: AW1haW4tMjUxMjExMDAzNSBTYWx0ZWRfX4VRvA2y0Obu2 bBFe6ntUsGGBOh/QUBoNiK/cWTn1L1VdMDO8IT/tzV0MEYy0LHBwMmgpyD/NyeM5Lznx1+UMgoo 0UsmfP9xyR/hyKO3euyagfAYxO+QUwuTO8lHjSrgNLH6eCmc99Xafuqq50VpQldjdU+GApSiQU0 gRdT0+qNJhr7/vJ1+s0vCnGHwKuXwd14p/ce5vI/q02E9H0Lm3xhrGwMWCnJeKKrBxlLVh/WnkF GgmTYvaSbHeJ5TcbsL68KkShe+2OBnHcdiEseIUDqzr4vnxWrxmxDC76ddzLj/DAyvjoaCVedcf UVz6IwgRLYlUrZkH2exGtB1abHLTTfzzliDCP8ez9mTJP9So4V4yGWl02mLDkEFvkGmfx5bbTrR ONhzd9SlT7HeIFXPI5EZ9qPPi4vLfg== X-Authority-Analysis: v=2.4 cv=deGNHHXe c=1 sm=1 tr=0 ts=693a559a cx=c_pps a=0uOsjrqzRL749jD1oC5vDA==:117 a=ZePRamnt/+rB5gQjfz0u9A==:17 a=IkcTkHD0fZMA:10 a=wP3pNCr1ah4A:10 a=s4-Qcg_JpJYA:10 a=VkNPw1HP01LnGYTKEx00:22 a=EUspDBNiAAAA:8 a=-TY5rVZSftfygaBM3lQA:9 a=3ZKOabzyN94A:10 a=QEXdDO2ut3YA:10 a=mQ_c8vxmzFEMiUWkPHU9:22 X-Proofpoint-GUID: 6pboxDCxD_4OFxVajVngef09y-Zn1t_F X-Proofpoint-ORIG-GUID: 6pboxDCxD_4OFxVajVngef09y-Zn1t_F 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=2025-12-10_03,2025-12-09_03,2025-10-01_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 adultscore=0 clxscore=1015 phishscore=0 suspectscore=0 malwarescore=0 bulkscore=0 priorityscore=1501 lowpriorityscore=0 impostorscore=0 spamscore=0 classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.22.0-2510240001 definitions=main-2512110035 On Fri, Nov 07, 2025 at 04:11:15PM +0100, Marek Vasut wrote: > On 11/7/25 2:52 PM, Nilesh Laad wrote: > > On Fri, Nov 07, 2025 at 02:20:58PM +0100, Marek Vasut wrote: > > > On 11/7/25 2:02 PM, Nilesh Laad wrote: > > > > From: Yi Zhang > > > > > > > > LT9211c is a Single/Dual-Link DSI/LVDS or Single DPI input to > > > > Single-link/Dual-Link DSI/LVDS or Single DPI output bridge chip. > > > > Add support for DSI to LVDS bridge configuration. > > > How does this differ from existing drivers/gpu/drm/bridge/lontium-lt9211.c ? > > > Can existing lt9211 driver be extended instead ? If not, why ? Details > > > please ... > > LT9211 and LT9211C differ completely in register programming sequences. > > Even lontium mentioned that register configuration are different for lt9211 and lt9211c. > > Lontium seems to often suggest, that users should use their provided > register patches without thinking about the content at all. > > Do you have access to the register documentation, and can you compare LT9211 > and LT9211C register layout? Are they identical or do they differ? We don’t have access to register documentation. Based on Lontium provided reference code, register sequences differ. We are seeing this limited difference, we plan to extend the existing lontium‑lt9211 driver to support LT9211C. Will share a patch with these changes. > > Nearly every function would require duplicated logic with if (chip_type) branching, > > as register sequence are completely different. > > Having both sequences in single file is not looking good, hence want to merge as separate driver. > > Can we somehow use regmap_register_patch() and register patches in driver > data to avoid duplication ? Using regmap_register_patch() would not reduce duplication. The bridge configuration between LT9211 and LT9211C are different, leaving minimal common base and still requiring separate calculation logic and control flow. > -- > Best regards, > Marek Vasut