| Message ID | 20171013155946.1486-1-l.stach@pengutronix.de (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 9ce70d49fa80b95a029c16432270f4edbbd2a953 |
| Headers | show |
On Fri, Oct 13, 2017 at 05:59:46PM +0200, Lucas Stach wrote: > Fix this by skipping all known alias numbers when assigning the dynamic IDs. > - id = idr_alloc(&spi_master_idr, ctlr, SPI_DYN_FIRST_BUS_NUM, 0, > - GFP_KERNEL); > + id = idr_alloc(&spi_master_idr, ctlr, > + of_alias_get_highest_id("spi") + 1, > + 0, GFP_KERNEL); I'll apply this but I'm wondering if we want to have the static bus number allocation also allocate that number out of the IDR so the IDR code handles things more transparently. Feels like it's more trouble than it's worth though, this should work fine. I'm also worrying about the case where IDR allocated a number before a static assignment got to it... not much we can do to guarantee that we avoid that case though.
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index 6e65524cbfd9..0483410e7cb3 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -45,7 +45,6 @@ #define CREATE_TRACE_POINTS #include <trace/events/spi.h> -#define SPI_DYN_FIRST_BUS_NUM 0 static DEFINE_IDR(spi_master_idr); @@ -2117,8 +2116,9 @@ int spi_register_controller(struct spi_controller *ctlr) } if (ctlr->bus_num < 0) { mutex_lock(&board_lock); - id = idr_alloc(&spi_master_idr, ctlr, SPI_DYN_FIRST_BUS_NUM, 0, - GFP_KERNEL); + id = idr_alloc(&spi_master_idr, ctlr, + of_alias_get_highest_id("spi") + 1, + 0, GFP_KERNEL); mutex_unlock(&board_lock); if (WARN(id < 0, "couldn't get idr")) return id;
On systems where some controllers get a dynamic ID assigned and some have a fixed number from DT, the current implemention might run into an IDR collision if the dynamic controllers gets probed first and get an IDR number, which is later requested by the controller with the fixed numbering. When this happens the fixed controller will fail to register with the SPI core. Fix this by skipping all known alias numbers when assigning the dynamic IDs. Fixes: 9b61e302210e (spi: Pick spi bus number from Linux idr or spi alias) Signed-off-by: Lucas Stach <l.stach@pengutronix.de> --- drivers/spi/spi.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)