Please see the bisection report below about a boot failure. Reports aren't automatically sent to the public while we're trialing new bisection features on kernelci.org but this one looks valid. Guillaume On 29/01/2020 23:00, kernelci.org bot wrote: > * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * > * This automated bisection report was sent to you on the basis * > * that you may be involved with the breaking commit it has * > * found. No manual investigation has been done to verify it, * > * and the root cause of the problem may be somewhere else. * > * * > * If you do send a fix, please include this trailer: * > * Reported-by: "kernelci.org bot" <bot@xxxxxxxxxxxx> * > * * > * Hope this helps! * > * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * > > mainline/master bisection: baseline.login on odroid-xu3 > > Summary: > Start: b3a608222336 Merge branch 'for-v5.6' of git://git.kernel.org:/pub/scm/linux/kernel/git/jmorris/linux-security > Plain log: https://storage.kernelci.org//mainline/master/v5.5-3996-gb3a608222336/arm/multi_v7_defconfig+CONFIG_SMP=n/gcc-8/lab-collabora/baseline-exynos5422-odroidxu3.txt > HTML log: https://storage.kernelci.org//mainline/master/v5.5-3996-gb3a608222336/arm/multi_v7_defconfig+CONFIG_SMP=n/gcc-8/lab-collabora/baseline-exynos5422-odroidxu3.html > Result: 71723a96b8b1 dmaengine: Create symlinks between DMA channels and slaves > > Checks: > revert: PASS > verify: PASS > > Parameters: > Tree: mainline > URL: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git > Branch: master > Target: odroid-xu3 > CPU arch: arm > Lab: lab-collabora > Compiler: gcc-8 > Config: multi_v7_defconfig+CONFIG_SMP=n > Test case: baseline.login > > Breaking commit found: > > ------------------------------------------------------------------------------- > commit 71723a96b8b1367fefc18f60025dae792477d602 > Author: Geert Uytterhoeven <geert+renesas@xxxxxxxxx> > Date: Fri Jan 17 16:30:56 2020 +0100 > > dmaengine: Create symlinks between DMA channels and slaves > > Currently it is not easy to find out which DMA channels are in use, and > which slave devices are using which channels. > > Fix this by creating two symlinks between the DMA channel and the actual > slave device when a channel is requested: > 1. A "slave" symlink from DMA channel to slave device, > 2. A "dma:<name>" symlink slave device to DMA channel. > When the channel is released, the symlinks are removed again. > The latter requires keeping track of the slave device and the channel > name in the dma_chan structure. > > Note that this is limited to channel request functions for requesting an > exclusive slave channel that take a device pointer (dma_request_chan() > and dma_request_slave_channel*()). > > Signed-off-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx> > Tested-by: Niklas Söderlund <niklas.soderlund@xxxxxxxxxxxx> > Link: https://lore.kernel.org/r/20200117153056.31363-1-geert+renesas@xxxxxxxxx > Signed-off-by: Vinod Koul <vkoul@xxxxxxxxxx> > > diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c > index 51a2f2b1b2de..f3ef4edd4de1 100644 > --- a/drivers/dma/dmaengine.c > +++ b/drivers/dma/dmaengine.c > @@ -60,6 +60,8 @@ static long dmaengine_ref_count; > > /* --- sysfs implementation --- */ > > +#define DMA_SLAVE_NAME "slave" > + > /** > * dev_to_dma_chan - convert a device pointer to its sysfs container object > * @dev - device node > @@ -730,11 +732,11 @@ struct dma_chan *dma_request_chan(struct device *dev, const char *name) > if (has_acpi_companion(dev) && !chan) > chan = acpi_dma_request_slave_chan_by_name(dev, name); > > - if (chan) { > - /* Valid channel found or requester needs to be deferred */ > - if (!IS_ERR(chan) || PTR_ERR(chan) == -EPROBE_DEFER) > - return chan; > - } > + if (PTR_ERR(chan) == -EPROBE_DEFER) > + return chan; > + > + if (!IS_ERR_OR_NULL(chan)) > + goto found; > > /* Try to find the channel via the DMA filter map(s) */ > mutex_lock(&dma_list_mutex); > @@ -754,7 +756,23 @@ struct dma_chan *dma_request_chan(struct device *dev, const char *name) > } > mutex_unlock(&dma_list_mutex); > > - return chan ? chan : ERR_PTR(-EPROBE_DEFER); > + if (!IS_ERR_OR_NULL(chan)) > + goto found; > + > + return ERR_PTR(-EPROBE_DEFER); > + > +found: > + chan->slave = dev; > + chan->name = kasprintf(GFP_KERNEL, "dma:%s", name); > + if (!chan->name) > + return ERR_PTR(-ENOMEM); > + > + if (sysfs_create_link(&chan->dev->device.kobj, &dev->kobj, > + DMA_SLAVE_NAME)) > + dev_err(dev, "Cannot create DMA %s symlink\n", DMA_SLAVE_NAME); > + if (sysfs_create_link(&dev->kobj, &chan->dev->device.kobj, chan->name)) > + dev_err(dev, "Cannot create DMA %s symlink\n", chan->name); > + return chan; > } > EXPORT_SYMBOL_GPL(dma_request_chan); > > @@ -812,6 +830,13 @@ void dma_release_channel(struct dma_chan *chan) > /* drop PRIVATE cap enabled by __dma_request_channel() */ > if (--chan->device->privatecnt == 0) > dma_cap_clear(DMA_PRIVATE, chan->device->cap_mask); > + if (chan->slave) { > + sysfs_remove_link(&chan->slave->kobj, chan->name); > + kfree(chan->name); > + chan->name = NULL; > + chan->slave = NULL; > + } > + sysfs_remove_link(&chan->dev->device.kobj, DMA_SLAVE_NAME); > mutex_unlock(&dma_list_mutex); > } > EXPORT_SYMBOL_GPL(dma_release_channel); > diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h > index f52f274773ed..fef69a9c5824 100644 > --- a/include/linux/dmaengine.h > +++ b/include/linux/dmaengine.h > @@ -294,10 +294,12 @@ struct dma_router { > /** > * struct dma_chan - devices supply DMA channels, clients use them > * @device: ptr to the dma device who supplies this channel, always !%NULL > + * @slave: ptr to the device using this channel > * @cookie: last cookie value returned to client > * @completed_cookie: last completed cookie for this channel > * @chan_id: channel ID for sysfs > * @dev: class device for sysfs > + * @name: backlink name for sysfs > * @device_node: used to add this to the device chan list > * @local: per-cpu pointer to a struct dma_chan_percpu > * @client_count: how many clients are using this channel > @@ -308,12 +310,14 @@ struct dma_router { > */ > struct dma_chan { > struct dma_device *device; > + struct device *slave; > dma_cookie_t cookie; > dma_cookie_t completed_cookie; > > /* sysfs */ > int chan_id; > struct dma_chan_dev *dev; > + const char *name; > > struct list_head device_node; > struct dma_chan_percpu __percpu *local; > ------------------------------------------------------------------------------- > > > Git bisection log: > > ------------------------------------------------------------------------------- > git bisect start > # good: [4703d9119972bf586d2cca76ec6438f819ffa30e] Merge tag 'xarray-5.5' of git://git.infradead.org/users/willy/linux-dax > git bisect good 4703d9119972bf586d2cca76ec6438f819ffa30e > # bad: [b3a6082223369203d7e7db7e81253ac761377644] Merge branch 'for-v5.6' of git://git.kernel.org:/pub/scm/linux/kernel/git/jmorris/linux-security > git bisect bad b3a6082223369203d7e7db7e81253ac761377644 > # bad: [a78208e2436963d0b2c7d186277d6e1a9755029a] Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 > git bisect bad a78208e2436963d0b2c7d186277d6e1a9755029a > # bad: [b1dba2473114588be3df916bf629a61bdcc83737] Merge tag 'selinux-pr-20200127' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux > git bisect bad b1dba2473114588be3df916bf629a61bdcc83737 > # good: [9e1af7567b266dc6c3c8fd434ea807b3206bfdc1] Merge tag 'mmc-v5.6' of git://git.kernel.org/pub/scm/linux/kernel/git/ulfh/mmc > git bisect good 9e1af7567b266dc6c3c8fd434ea807b3206bfdc1 > # bad: [aae1464f46a2403565f75717438118691d31ccf1] Merge tag 'regulator-v5.6' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator > git bisect bad aae1464f46a2403565f75717438118691d31ccf1 > # bad: [a5b871c91d470326eed3ae0ebd2fc07f3aee9050] Merge tag 'dmaengine-5.6-rc1' of git://git.infradead.org/users/vkoul/slave-dma > git bisect bad a5b871c91d470326eed3ae0ebd2fc07f3aee9050 > # good: [12fb2b993e1508a0d9032a2314dfdda2a3a5535e] Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/hid/hid > git bisect good 12fb2b993e1508a0d9032a2314dfdda2a3a5535e > # good: [7d083ae983573de16e3ab0bfd47486996d211417] dmaengine: doc: Add sections for per descriptor metadata support > git bisect good 7d083ae983573de16e3ab0bfd47486996d211417 > # good: [e606c8b9d751e593b71bdcb636ac3392c62c1c50] dmaengine: s3c24xx-dma: fix spelling mistake "to" -> "too" > git bisect good e606c8b9d751e593b71bdcb636ac3392c62c1c50 > # good: [8f47d1a5e545f903cd049c42da31a3be36178447] dmaengine: idxd: connect idxd to dmaengine subsystem > git bisect good 8f47d1a5e545f903cd049c42da31a3be36178447 > # good: [f46e49a9cc3814f3564477f0fffc00e0a2bc9e80] livepatch: Handle allocation failure in the sample of shadow variable API > git bisect good f46e49a9cc3814f3564477f0fffc00e0a2bc9e80 > # good: [e9f08b65250d73ab70e79e194813f52b8d306784] dmaengine: hisilicon: Add Kunpeng DMA engine support > git bisect good e9f08b65250d73ab70e79e194813f52b8d306784 > # bad: [71723a96b8b1367fefc18f60025dae792477d602] dmaengine: Create symlinks between DMA channels and slaves > git bisect bad 71723a96b8b1367fefc18f60025dae792477d602 > # first bad commit: [71723a96b8b1367fefc18f60025dae792477d602] dmaengine: Create symlinks between DMA channels and slaves > ------------------------------------------------------------------------------- >
