From 187cfc439f7b1a7c91ff72d561b2a7c9c0b83431 Mon Sep 17 00:00:00 2001 From: Benjamin Herrenschmidt Date: Mon, 9 Mar 2009 14:36:15 +0000 Subject: hvc_console: Remove tty->low_latency on pseries backends The hvcs and hvsi backends both set tty->low_latency to one, along with more or less scary comments regarding bugs or races that would happen if not doing so. However, they also both call tty_flip_buffer_push() in conexts where it's illegal to do so since some recent tty changes (or at least it may have been illegal always but it nows blows) when low_latency is set (ie, hard interrupt or with spinlock held and irqs disabled). This removes the setting for now to get them back to working condition, we'll have to address the races described in the comments separately if they are still an issue (some of this might have been fixed already). Signed-off-by: Benjamin Herrenschmidt --- drivers/char/hvcs.c | 9 --------- drivers/char/hvsi.c | 1 - 2 files changed, 10 deletions(-) (limited to 'drivers/char') diff --git a/drivers/char/hvcs.c b/drivers/char/hvcs.c index 6e6eb445d374..c76bccf5354d 100644 --- a/drivers/char/hvcs.c +++ b/drivers/char/hvcs.c @@ -1139,15 +1139,6 @@ static int hvcs_open(struct tty_struct *tty, struct file *filp) hvcsd->tty = tty; tty->driver_data = hvcsd; - /* - * Set this driver to low latency so that we actually have a chance at - * catching a throttled TTY after we flip_buffer_push. Otherwise the - * flush_to_async may not execute until after the kernel_thread has - * yielded and resumed the next flip_buffer_push resulting in data - * loss. - */ - tty->low_latency = 1; - memset(&hvcsd->buffer[0], 0x00, HVCS_BUFF_LEN); /* diff --git a/drivers/char/hvsi.c b/drivers/char/hvsi.c index 406f8742a260..2989056a9e39 100644 --- a/drivers/char/hvsi.c +++ b/drivers/char/hvsi.c @@ -810,7 +810,6 @@ static int hvsi_open(struct tty_struct *tty, struct file *filp) hp = &hvsi_ports[line]; tty->driver_data = hp; - tty->low_latency = 1; /* avoid throttle/tty_flip_buffer_push race */ mb(); if (hp->state == HVSI_FSP_DIED) -- cgit v1.2.3 From bfe4f4f800ccbb499a1120735016a20d3feacd4f Mon Sep 17 00:00:00 2001 From: James Bottomley Date: Fri, 9 Jan 2009 18:57:06 -0600 Subject: parisc: remove klist iterators commit 11c3b5c3e08f4d855cbef52883c266b9ab9df879 Author: Greg Kroah-Hartman Date: Tue Dec 16 12:24:56 2008 -0800 driver core: move klist_children into private structure Broke our parisc build pretty badly because we touch the klists directly in three cases (AGP, SBA and GSC). Although GregKH will revert this patch, there's no reason we should be using the iterators directly, we can just move to the standard device_for_each_child() API. Signed-off-by: James Bottomley Tested-by: Helge Deller Tested-by: Kyle McMartin Signed-off-by: Kyle McMartin --- drivers/char/agp/parisc-agp.c | 23 ++++++++-------- drivers/parisc/gsc.c | 39 +++++++++++++++------------ drivers/parisc/sba_iommu.c | 61 +++++++++++++++++++++++++------------------ 3 files changed, 68 insertions(+), 55 deletions(-) (limited to 'drivers/char') diff --git a/drivers/char/agp/parisc-agp.c b/drivers/char/agp/parisc-agp.c index db60539bf67a..699e3422ad93 100644 --- a/drivers/char/agp/parisc-agp.c +++ b/drivers/char/agp/parisc-agp.c @@ -359,9 +359,16 @@ fail: return error; } -static struct device *next_device(struct klist_iter *i) { - struct klist_node * n = klist_next(i); - return n ? container_of(n, struct device, knode_parent) : NULL; +static int +find_quicksilver(struct device *dev, void *data) +{ + struct parisc_device **lba = data; + struct parisc_device *padev = to_parisc_device(dev); + + if (IS_QUICKSILVER(padev)) + *lba = padev; + + return 0; } static int @@ -372,8 +379,6 @@ parisc_agp_init(void) int err = -1; struct parisc_device *sba = NULL, *lba = NULL; struct lba_device *lbadev = NULL; - struct device *dev = NULL; - struct klist_iter i; if (!sba_list) goto out; @@ -386,13 +391,7 @@ parisc_agp_init(void) } /* Now search our Pluto for our precious AGP device... */ - klist_iter_init(&sba->dev.klist_children, &i); - while ((dev = next_device(&i))) { - struct parisc_device *padev = to_parisc_device(dev); - if (IS_QUICKSILVER(padev)) - lba = padev; - } - klist_iter_exit(&i); + device_for_each_child(&sba->dev, &lba, find_quicksilver); if (!lba) { printk(KERN_INFO DRVPFX "No AGP devices found.\n"); diff --git a/drivers/parisc/gsc.c b/drivers/parisc/gsc.c index e76db9e4d504..d33632917696 100644 --- a/drivers/parisc/gsc.c +++ b/drivers/parisc/gsc.c @@ -186,29 +186,34 @@ void gsc_asic_assign_irq(struct gsc_asic *asic, int local_irq, int *irqp) *irqp = irq; } -static struct device *next_device(struct klist_iter *i) +struct gsc_fixup_struct { + void (*choose_irq)(struct parisc_device *, void *); + void *ctrl; +}; + +static int gsc_fixup_irqs_callback(struct device *dev, void *data) { - struct klist_node * n = klist_next(i); - return n ? container_of(n, struct device, knode_parent) : NULL; + struct parisc_device *padev = to_parisc_device(dev); + struct gsc_fixup_struct *gf = data; + + /* work-around for 715/64 and others which have parent + at path [5] and children at path [5/0/x] */ + if (padev->id.hw_type == HPHW_FAULTY) + gsc_fixup_irqs(padev, gf->ctrl, gf->choose_irq); + gf->choose_irq(padev, gf->ctrl); + + return 0; } void gsc_fixup_irqs(struct parisc_device *parent, void *ctrl, void (*choose_irq)(struct parisc_device *, void *)) { - struct device *dev; - struct klist_iter i; - - klist_iter_init(&parent->dev.klist_children, &i); - while ((dev = next_device(&i))) { - struct parisc_device *padev = to_parisc_device(dev); - - /* work-around for 715/64 and others which have parent - at path [5] and children at path [5/0/x] */ - if (padev->id.hw_type == HPHW_FAULTY) - return gsc_fixup_irqs(padev, ctrl, choose_irq); - choose_irq(padev, ctrl); - } - klist_iter_exit(&i); + struct gsc_fixup_struct data = { + .choose_irq = choose_irq, + .ctrl = ctrl, + }; + + device_for_each_child(&parent->dev, &data, gsc_fixup_irqs_callback); } int gsc_common_setup(struct parisc_device *parent, struct gsc_asic *gsc_asic) diff --git a/drivers/parisc/sba_iommu.c b/drivers/parisc/sba_iommu.c index a70cf16ee1ad..6aad8546fd24 100644 --- a/drivers/parisc/sba_iommu.c +++ b/drivers/parisc/sba_iommu.c @@ -1206,31 +1206,49 @@ sba_alloc_pdir(unsigned int pdir_size) return (void *) pdir_base; } -static struct device *next_device(struct klist_iter *i) +struct ibase_data_struct { + struct ioc *ioc; + int ioc_num; +}; + +static int setup_ibase_imask_callback(struct device *dev, void *data) { - struct klist_node * n = klist_next(i); - return n ? container_of(n, struct device, knode_parent) : NULL; + /* lba_set_iregs() is in drivers/parisc/lba_pci.c */ + extern void lba_set_iregs(struct parisc_device *, u32, u32); + struct parisc_device *lba = to_parisc_device(dev); + struct ibase_data_struct *ibd = data; + int rope_num = (lba->hpa.start >> 13) & 0xf; + if (rope_num >> 3 == ibd->ioc_num) + lba_set_iregs(lba, ibd->ioc->ibase, ibd->ioc->imask); + return 0; } /* setup Mercury or Elroy IBASE/IMASK registers. */ static void setup_ibase_imask(struct parisc_device *sba, struct ioc *ioc, int ioc_num) { - /* lba_set_iregs() is in drivers/parisc/lba_pci.c */ - extern void lba_set_iregs(struct parisc_device *, u32, u32); - struct device *dev; - struct klist_iter i; - - klist_iter_init(&sba->dev.klist_children, &i); - while ((dev = next_device(&i))) { - struct parisc_device *lba = to_parisc_device(dev); - int rope_num = (lba->hpa.start >> 13) & 0xf; - if (rope_num >> 3 == ioc_num) - lba_set_iregs(lba, ioc->ibase, ioc->imask); - } - klist_iter_exit(&i); + struct ibase_data_struct ibase_data = { + .ioc = ioc, + .ioc_num = ioc_num, + }; + + device_for_each_child(&sba->dev, &ibase_data, + setup_ibase_imask_callback); } +#ifdef SBA_AGP_SUPPORT +static int +sba_ioc_find_quicksilver(struct device *dev, void *data) +{ + int *agp_found = data; + struct parisc_device *lba = to_parisc_device(dev); + + if (IS_QUICKSILVER(lba)) + *agp_found = 1; + return 0; +} +#endif + static void sba_ioc_init_pluto(struct parisc_device *sba, struct ioc *ioc, int ioc_num) { @@ -1332,9 +1350,6 @@ sba_ioc_init_pluto(struct parisc_device *sba, struct ioc *ioc, int ioc_num) WRITE_REG(ioc->ibase | 31, ioc->ioc_hpa + IOC_PCOM); #ifdef SBA_AGP_SUPPORT -{ - struct klist_iter i; - struct device *dev = NULL; /* ** If an AGP device is present, only use half of the IOV space @@ -1344,13 +1359,7 @@ sba_ioc_init_pluto(struct parisc_device *sba, struct ioc *ioc, int ioc_num) ** We program the next pdir index after we stop w/ a key for ** the GART code to handshake on. */ - klist_iter_init(&sba->dev.klist_children, &i); - while ((dev = next_device(&i))) { - struct parisc_device *lba = to_parisc_device(dev); - if (IS_QUICKSILVER(lba)) - agp_found = 1; - } - klist_iter_exit(&i); + device_for_each_child(&sba->dev, &agp_found, sba_ioc_find_quicksilver); if (agp_found && sba_reserve_agpgart) { printk(KERN_INFO "%s: reserving %dMb of IOVA space for agpgart\n", -- cgit v1.2.3