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[142.162.112.119]) by smtp.gmail.com with ESMTPSA id d75a77b69052e-5063915d649sm360431cf.12.2026.02.05.09.33.47 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 05 Feb 2026 09:33:47 -0800 (PST) Received: from jgg by wakko with local (Exim 4.97) (envelope-from ) id 1vo3Eg-00000001qDl-348S; Thu, 05 Feb 2026 13:33:46 -0400 Date: Thu, 5 Feb 2026 13:33:46 -0400 From: Jason Gunthorpe To: Pavan Chebbi Cc: Saeed Mahameed , michael.chan@broadcom.com, linux-kernel@vger.kernel.org, dave.jiang@intel.com, Jonathan.Cameron@huawei.com, gospo@broadcom.com, selvin.xavier@broadcom.com, leon@kernel.org, kalesh-anakkur.purayil@broadcom.com Subject: Re: [PATCH v3 fwctl 4/5] fwctl/bnxt_fwctl: Add bnxt fwctl device Message-ID: <20260205173346.GO2328995@ziepe.ca> References: <20260129155453.3626544-1-pavan.chebbi@broadcom.com> <20260129155453.3626544-5-pavan.chebbi@broadcom.com> Precedence: bulk X-Mailing-List: linux-kernel@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: On Thu, Feb 05, 2026 at 09:55:08AM +0530, Pavan Chebbi wrote: > > > > I find it a bit weird that the user needs to provide dma information and > > structure ! this is supposed to be completely hidden by the driver to > > simplify user space, the driver handles dma and access to HW, user space > > just provides the commands and payloads and driver carries the input/output > > for that user space. > > This is so because our FW commands require optional DMA-able buffers. > The application is only giving us the information that the driver > should encapsulate in additional DMA-able buffers. > There is a defined format for exchange of this information, because > every command has a different number of additional buffers. Also the > majority of the commands don't need any additional buffers. > I hope this answers your next comments also. Now I have questions, who allocates these buffers, how do they get DMA mapped, who does all the copying?? Jason