From: Takashi Iwai tiwai@suse.de

[ Upstream commit 69458e2c27800da7697c87ed908b65323ef3f3bd ]

HD-audio driver handles the multiple instances and keeps the static index that is incremented at each probe. This becomes a problem when user tries to re-bind the device via sysfs multiple times; as the device index isn't cleared unlike rmmod case, it points to the next element at re-binding, and eventually later you can't probe any more when it reaches to SNDRV_CARDS_MAX (usually 32).

This patch is an attempt to improve the handling at rebinding. Instead of a static device index, now we keep a bitmap and assigns to the first zero bit position. At the driver remove, in return, the bitmap slot is cleared again, so that it'll be available for the next probe.

Reported-by: Alexander Sergeyev sergeev917@gmail.com Link: https://lore.kernel.org/r/20220209081912.20687-1-tiwai@suse.de Signed-off-by: Takashi Iwai tiwai@suse.de Signed-off-by: Sasha Levin sashal@kernel.org --- sound/pci/hda/hda_intel.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c index 572ff0d1fafe..8eff25d2d9e6 100644 --- a/sound/pci/hda/hda_intel.c +++ b/sound/pci/hda/hda_intel.c @@ -2066,14 +2066,16 @@ static const struct hda_controller_ops pci_hda_ops = { .position_check = azx_position_check, };

+static DECLARE_BITMAP(probed_devs, SNDRV_CARDS); + static int azx_probe(struct pci_dev *pci, const struct pci_device_id *pci_id) { - static int dev; struct snd_card *card; struct hda_intel *hda; struct azx *chip; bool schedule_probe; + int dev; int err;

if (pci_match_id(driver_denylist, pci)) { @@ -2081,10 +2083,11 @@ static int azx_probe(struct pci_dev *pci, return -ENODEV; }

+ dev = find_first_zero_bit(probed_devs, SNDRV_CARDS); if (dev >= SNDRV_CARDS) return -ENODEV; if (!enable[dev]) { - dev++; + set_bit(dev, probed_devs); return -ENOENT; }

@@ -2151,7 +2154,7 @@ static int azx_probe(struct pci_dev *pci, if (schedule_probe) schedule_delayed_work(&hda->probe_work, 0);

- dev++; + set_bit(dev, probed_devs); if (chip->disabled) complete_all(&hda->probe_wait); return 0; @@ -2374,6 +2377,7 @@ static void azx_remove(struct pci_dev *pci) cancel_delayed_work_sync(&hda->probe_work); device_lock(&pci->dev);

+ clear_bit(chip->dev_index, probed_devs); pci_set_drvdata(pci, NULL); snd_card_free(card); }