From mboxrd@z Thu Jan 1 00:00:00 1970 From: James Bottomley Subject: Re: [PATCH 1/2] don't wait on disk to start on resume Date: Fri, 01 Feb 2013 09:27:37 +1100 Message-ID: <1359671257.7527.4.camel@dabdike> References: <1356064540-17414-1-git-send-email-dbasehore@chromium.org> <50D5C473.2030902@mvista.com> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-15" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org To: "dbasehore ." Cc: Sergei Shtylyov , jgarzik@pobox.com, linux-ide@vger.kernel.org, linux-kernel , linux-scsi List-Id: linux-ide@vger.kernel.org On Thu, 2013-01-31 at 14:00 -0800, dbasehore . wrote: > (Resending as plain text so the message is tracked on vger) > > Hi, thanks for reading through my patch. > > With regards to SCSI_SENSE_BUFFERSIZE, I'm following the precedent of > scsi_execute_req found in drivers/scsi/scsi_lib.c I have no context for this: I don't recall making any comment on sense buffers; what are you replying to? James > It seems that it is used by the scsi_normalize_sense function which I > call in sd_resume_async. I just input SCSI_SENSE_BUFFERSIZE directly > there though. I didn't know if anything would change its behavior on a > lower level if I made sense_len = SCSI_SENSE_BUFFERSIZE, so I just > went with what was already done. > > I'll make sure the semantic fixes go into the final patch. > > Also, I forgot to mention one possible problem earlier. I understand > that some hard drives have a command buffer that can be executed by > the hard drive in an order it determines. Does anyone know of a > potential problem if the following happens? > > -resume finishes (hard drive not started yet) > -read/write sent to disk, inserted before start command > > Could this happen? If so, could it cause any problems? > > I've tested the possibility of a program trying to read/write from the > disk before it has started, and the read/write blocks until the disk > has actually been spun up. I don't know if there are specific hard > drives where this could be a problem though. > -- > To unsubscribe from this list: send the line "unsubscribe linux-scsi" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html