Hi John, Well I could see this kernel panic [ 126.843958] RIP: 0010:pm80xx_chip_smp_req+0x1d6/0x2e0 [pm80xx] with respect to existing driver on my current system x86 64bit after enabling the following 2 kernel boot arguments: -intel_iommu=on -iommu.passthrough=0 Post application of this patch, now not observing the kernel panic and device discovery happens smoothly. Thanks, Ajish -----Original Message----- From: Niklas Cassel <Niklas.Cassel@xxxxxxx> Sent: Monday, December 6, 2021 06:54 PM To: John Garry <john.garry@xxxxxxxxxx> Cc: Ajish Koshy - I30923 <Ajish.Koshy@xxxxxxxxxxxxx>; jinpu.wang@xxxxxxxxxxxxxxx; jejb@xxxxxxxxxxxxx; martin.petersen@xxxxxxxxxx; Viswas G - I30667 <Viswas.G@xxxxxxxxxxxxx>; linux-scsi@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; Damien Le Moal <damien.lemoal@xxxxxxxxxxxxxxxxxx> Subject: Re: [PATCH] scsi: pm8001: Fix phys_to_virt() usage on dma_addr_t [Some people who received this message don't often get email from niklas.cassel@xxxxxxx. Learn why this is important at http://aka.ms/LearnAboutSenderIdentification.] EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe On Mon, Dec 06, 2021 at 09:42:23AM +0000, John Garry wrote: > On 29/11/2021 10:46, Ajish.Koshy@xxxxxxxxxxxxx wrote: > > Thanks John for the update. Based on the given issue, > > we never tested on arm server. > > > > Further arm testing will depend on the availability of > > the server. > > > > Meanwhile will do further test on x86 and update > > on the observations. > > Have you tested on x86 with the IOMMU enabled? From my limited experience, > out of the box the IOMMU is disabled in the BIOS on x86 machines - that is a > very general statement. But this is not just an issue specific to arm64. My limited experience tells me the opposite, that modern x64 servers have IOMMU enabled by default: E.g.: https://www.dell.com/support/manuals/en-uk/poweredge-r7515/r7515_bios_pub/processor-settings?guid=guid-ec36d324-4f45-4bc1-bb51-de2db7cc5cd9&lang=en-us https://support.hpe.com/hpesc/public/docDisplay?docId=a00025662en_us&docLocale=en_US This driver not working properly on a system with an IOMMU just tells us that the number of mainline users of this driver is very low :/ Kind regards, Niklas
