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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: bwmzr+Z5Yc7q3a4cWwxG1zataOBmSKs+esVW+c1wIPVERkhwPXkOKGhekffglA+SVNCg+6qsIjDJbQqg3516I7bf5Updi+EZ89mJHQ0UH7OVxJivK/D1Pm9wLAzhFwZlEienoeLngm1s+MVCpgnacxuMqUYqbbwN7HfLBdmj+B/8H+goOSPDpAH0o5JqR1rL3+HHBhlsk0ujQW4T9FYj9tWiP/5ds0Gq6kobV8vf0cH60Y3OAqCPnFn2slAoOErSLEb1FOKuRNI3ZNpZWWyLoZMql/7DdyQStTgCFWwWPyK/QiCK5xuSKJKBZQHW+eE27y7XSw0BoG0+1czMzCd0B5VRk53JwP1vPP0NsXPlrOuwkwiW9e7xA8r/LAWNGMzdgvO7H0JjU7++4opQP+2RQUZjh6BFJbIyGcr5y3tpaaBfkmgclXWC2nclygIhJqu6 X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 21 Oct 2026 17:53:16.5677 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: abaa77b6-66fd-4aab-75a3-08df2f9c2f67 X-MS-Exchange-CrossTenant-Id: 43083d15-7273-40c1-b7db-39efd9ccc17a X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=43083d15-7273-40c1-b7db-39efd9ccc17a;Ip=[216.228.117.161];Helo=[mail.nvidia.com] X-MS-Exchange-CrossTenant-AuthSource: MW2PEPF00014677.namprd04.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: IA1PR12MB6090 On Wed, Oct 21, 2026 at 05:53:23PM +0100, John Garry wrote: > On 10/5/26 20:30, Nicolin Chen wrote: > > + /* > > + * In a kdump case (set when CR0_SMMUEN=1 and !GERROR_SFM_ERR), retain > > + * all the live CR0 fields, e.g. CR0_SMMUEN to avoid aborting in-flight > > + * DMA and CR0_ATSCHK to carry on the ATS-check policy, while clearing > > + * only the queue enable bits for this kernel to take over the queues. > > + * > > + * According to spec, updating STRTAB_BASE/CR1/CR2 when CR0_SMMUEN=1 is > > + * CONSTRAINED UNPREDICTABLE. So, skip those register updates and rely > > + * on the adopted stream table from the crashed kernel. > > + */ > > + if (smmu->options & ARM_SMMU_OPT_KDUMP_ADOPT) { > > + dev_info(smmu->dev, > > + "kdump: retaining SMMUEN for in-flight DMA\n"); > > + enables = reg & ~(CR0_CMDQEN | CR0_EVTQEN | CR0_PRIQEN); > > + goto reset_queues; > > nit: Is there some reason to separate the call to arm_smmu_write_reg_sync() > under the ARM_SMMU_OPT_KDUMP_ADOPT check, below? Hmm, I think it's left over the versions and they can be merged. I'll do it in v12. Thanks Nicolin