| Message ID | 20180813164810.16769-1-kirill.kapranov@compulab.co.il (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | spi:fix IDR collision on systems with both fixed and dynamic SPI bus numbers | expand |
On Mon, Aug 13, 2018 at 07:48:10PM +0300, Kirill Kapranov wrote: > On systems where some controllers get a dynamic ID assigned and some have > a fixed number (e.g. from ACPI tables), the current implementation might > run into an IDR collision: in case of a fixed bus number is gotten by a > driver (but not marked busy in IDR tree) and a driver with dynamic bus > number gets the same ID and predictably fails. Is this something that's actually happened for you? > + } else { > + /* devices with a fixed bus num must check-in with the num */ > + mutex_lock(&board_lock); The indentation here is weird, the comment isn't aligned with the code it's commenting on.
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index ec395a6baf9c..97e303185d5b 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -2170,6 +2170,15 @@ int spi_register_controller(struct spi_controller *ctlr) if (WARN(id < 0, "couldn't get idr")) return id; ctlr->bus_num = id; + } else { + /* devices with a fixed bus num must check-in with the num */ + mutex_lock(&board_lock); + id = idr_alloc(&spi_master_idr, ctlr, ctlr->bus_num, + ctlr->bus_num + 1, GFP_KERNEL); + mutex_unlock(&board_lock); + if (WARN(id < 0, "couldn't get idr")) + return id == -ENOSPC ? -EBUSY : id; + ctlr->bus_num = id; } INIT_LIST_HEAD(&ctlr->queue); spin_lock_init(&ctlr->queue_lock);
On systems where some controllers get a dynamic ID assigned and some have a fixed number (e.g. from ACPI tables), the current implementation might run into an IDR collision: in case of a fixed bus number is gotten by a driver (but not marked busy in IDR tree) and a driver with dynamic bus number gets the same ID and predictably fails. Fix this by means of checking-in fixed IDsin IDR as far as dynamic ones at the moment of the controller registration. Fixes: 9b61e302210e (spi: Pick spi bus number from Linux idr or spi alias) Signed-off-by: Kirill Kapranov <kirill.kapranov@compulab.co.il> --- drivers/spi/spi.c | 9 +++++++++ 1 file changed, 9 insertions(+)