[media.git/next] media: rc: ir-spi: constrain carrier frequency

[media-ci]

On Fri Jun 13 14:21:52 2025 +0300, Cosmin Tanislav wrote:
> Carrier frequency is currently unconstrained, allowing the SPI transfer
> to be allocated and filled only for it to be later rejected by the SPI
> controller since the frequency is too large.
> 
> Add a check to constrain the carrier frequency inside
> ir_spi_set_tx_carrier().
> 
> Also, move the number of bits per pulse to a macro since it is not used
> in multiple places.
> 
> Signed-off-by: Cosmin Tanislav <demonsin...@gmail.com>
> Signed-off-by: Sean Young <s...@mess.org>
> Signed-off-by: Hans Verkuil <hverk...@xs4all.nl>

Patch committed.

Thanks,
Hans Verkuil

 drivers/media/rc/ir-spi.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

---

diff --git a/drivers/media/rc/ir-spi.c b/drivers/media/rc/ir-spi.c
index 50e30e2fae22..0b54ad74cec0 100644
--- a/drivers/media/rc/ir-spi.c
+++ b/drivers/media/rc/ir-spi.c
@@ -21,6 +21,7 @@
 #define IR_SPI_DRIVER_NAME             "ir-spi"
 
 #define IR_SPI_DEFAULT_FREQUENCY       38000
+#define IR_SPI_BITS_PER_PULSE          16
 
 struct ir_spi_data {
        u32 freq;
@@ -70,7 +71,7 @@ static int ir_spi_tx(struct rc_dev *dev, unsigned int 
*buffer, unsigned int coun
 
        memset(&xfer, 0, sizeof(xfer));
 
-       xfer.speed_hz = idata->freq * 16;
+       xfer.speed_hz = idata->freq * IR_SPI_BITS_PER_PULSE;
        xfer.len = len * sizeof(*tx_buf);
        xfer.tx_buf = tx_buf;
 
@@ -98,6 +99,9 @@ static int ir_spi_set_tx_carrier(struct rc_dev *dev, u32 
carrier)
        if (!carrier)
                return -EINVAL;
 
+       if (carrier > idata->spi->max_speed_hz / IR_SPI_BITS_PER_PULSE)
+               return -EINVAL;
+
        idata->freq = carrier;
 
        return 0;