On Sat, Jan 19, 2013 at 01:46:15PM -0500, Alan Stern wrote: > On Sat, 19 Jan 2013, Aaron Lu wrote: > > I don't think we should drop such support. > > And the safest way to avoid such break is we refine the suspend > > condition for ODD, and using what ZPODD defined condition isn't that > > bad to me: > > - for tray type, no media inside and tray close; > > - for slot type, no media inside. > > While whether tray is closed or not may not be that important, but at > > least we should make sure there is no media inside. > > > > Thoughts? > > That sounds reasonable to me, at least as a first step. If people want > their CD drive to suspend, they can eject the disc. Here is an updated patch to address the problem, please review, thanks. Changes to v13: - Add PM get/put pair functions to all the block device operation functions; Move the existing PM get/put pair functions in sr_check_events to sr_block_check_events; - Add sr_runtime_suspend, it will check if there is media inside and if yes, avoid suspend. >From 378bf55810a1118ede481f45132b5c39af891d23 Mon Sep 17 00:00:00 2001 From: Aaron Lu <aaron.lu@xxxxxxxxx> Date: Wed, 26 Sep 2012 15:14:56 +0800 Subject: [RFC PATCH] scsi: sr: support runtime pm This patch adds runtime pm support for sr. It did this by increasing the runtime usage_count of the device when its block device is accessed. And decreasing the runtime usage_count of the device when the access is done. The idea is discussed here: http://thread.gmane.org/gmane.linux.acpi.devel/55243/focus=52703 and here: http://thread.gmane.org/gmane.linux.ide/53665/focus=58836 Signed-off-by: Aaron Lu <aaron.lu@xxxxxxxxx> --- drivers/scsi/sr.c | 42 +++++++++++++++++++++++++++++++++++++++--- 1 file changed, 39 insertions(+), 3 deletions(-) diff --git a/drivers/scsi/sr.c b/drivers/scsi/sr.c index 5fc97d2..2e8ddd7 100644 --- a/drivers/scsi/sr.c +++ b/drivers/scsi/sr.c @@ -45,6 +45,7 @@ #include <linux/blkdev.h> #include <linux/mutex.h> #include <linux/slab.h> +#include <linux/pm_runtime.h> #include <asm/uaccess.h> #include <scsi/scsi.h> @@ -79,6 +80,11 @@ static DEFINE_MUTEX(sr_mutex); static int sr_probe(struct device *); static int sr_remove(struct device *); static int sr_done(struct scsi_cmnd *); +static int sr_runtime_suspend(struct device *dev); + +static struct dev_pm_ops sr_pm_ops = { + .runtime_suspend = sr_runtime_suspend, +}; static struct scsi_driver sr_template = { .owner = THIS_MODULE, @@ -86,6 +92,7 @@ static struct scsi_driver sr_template = { .name = "sr", .probe = sr_probe, .remove = sr_remove, + .pm = &sr_pm_ops, }, .done = sr_done, }; @@ -131,6 +138,16 @@ static inline struct scsi_cd *scsi_cd(struct gendisk *disk) return container_of(disk->private_data, struct scsi_cd, driver); } +static int sr_runtime_suspend(struct device *dev) +{ + struct scsi_cd *cd = dev_get_drvdata(dev); + + if (cd->media_present) + return -EBUSY; + else + return 0; +} + /* * The get and put routines for the struct scsi_cd. Note this entity * has a scsi_device pointer and owns a reference to this. @@ -146,7 +163,8 @@ static inline struct scsi_cd *scsi_cd_get(struct gendisk *disk) kref_get(&cd->kref); if (scsi_device_get(cd->device)) goto out_put; - goto out; + if (!scsi_autopm_get_device(cd->device)) + goto out; out_put: kref_put(&cd->kref, sr_kref_release); @@ -162,6 +180,7 @@ static void scsi_cd_put(struct scsi_cd *cd) mutex_lock(&sr_ref_mutex); kref_put(&cd->kref, sr_kref_release); + scsi_autopm_put_device(sdev); scsi_device_put(sdev); mutex_unlock(&sr_ref_mutex); } @@ -540,6 +559,8 @@ static int sr_block_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd, void __user *argp = (void __user *)arg; int ret; + scsi_autopm_get_device(cd->device); + mutex_lock(&sr_mutex); /* @@ -571,6 +592,7 @@ static int sr_block_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd, out: mutex_unlock(&sr_mutex); + scsi_autopm_put_device(cd->device); return ret; } @@ -578,7 +600,13 @@ static unsigned int sr_block_check_events(struct gendisk *disk, unsigned int clearing) { struct scsi_cd *cd = scsi_cd(disk); - return cdrom_check_events(&cd->cdi, clearing); + unsigned int ret; + + scsi_autopm_get_device(cd->device); + ret = cdrom_check_events(&cd->cdi, clearing); + scsi_autopm_put_device(cd->device); + + return ret; } static int sr_block_revalidate_disk(struct gendisk *disk) @@ -586,12 +614,16 @@ static int sr_block_revalidate_disk(struct gendisk *disk) struct scsi_cd *cd = scsi_cd(disk); struct scsi_sense_hdr sshdr; + scsi_autopm_get_device(cd->device); + /* if the unit is not ready, nothing more to do */ if (scsi_test_unit_ready(cd->device, SR_TIMEOUT, MAX_RETRIES, &sshdr)) - return 0; + goto out; sr_cd_check(&cd->cdi); get_sectorsize(cd); +out: + scsi_autopm_put_device(cd->device); return 0; } @@ -718,6 +750,8 @@ static int sr_probe(struct device *dev) sdev_printk(KERN_DEBUG, sdev, "Attached scsi CD-ROM %s\n", cd->cdi.name); + scsi_autopm_put_device(cd->device); + return 0; fail_put: @@ -965,6 +999,8 @@ static int sr_remove(struct device *dev) { struct scsi_cd *cd = dev_get_drvdata(dev); + scsi_autopm_get_device(cd->device); + blk_queue_prep_rq(cd->device->request_queue, scsi_prep_fn); del_gendisk(cd->disk); -- 1.8.1 Thanks, Aaron -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
