From 6ed4e39cb6eac644bcc47352a32d46ff80674f70 Mon Sep 17 00:00:00 2001 From: Oliver Neukum Date: Fri, 1 May 2026 13:27:52 -0400 Subject: [PATCH] media: rc: ttusbir: respect DMA coherency rules [ Upstream commit 50acaad3d202c064779db8dc3d010007347f59c7 ] Buffers must not share a cache line with other data structures. Allocate separately. Fixes: 0938069fa0897 ("[media] rc: Add support for the TechnoTrend USB IR Receiver") Cc: stable@vger.kernel.org Signed-off-by: Oliver Neukum Signed-off-by: Sean Young Signed-off-by: Hans Verkuil [ kept kzalloc(sizeof(*tt), GFP_KERNEL) instead of kzalloc_obj() ] Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/media/rc/ttusbir.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) diff --git a/drivers/media/rc/ttusbir.c b/drivers/media/rc/ttusbir.c index 629787d53ee1..91907c0262bd 100644 --- a/drivers/media/rc/ttusbir.c +++ b/drivers/media/rc/ttusbir.c @@ -32,7 +32,7 @@ struct ttusbir { struct led_classdev led; struct urb *bulk_urb; - uint8_t bulk_buffer[5]; + u8 *bulk_buffer; int bulk_out_endp, iso_in_endp; bool led_on, is_led_on; atomic_t led_complete; @@ -188,13 +188,16 @@ static int ttusbir_probe(struct usb_interface *intf, struct rc_dev *rc; int i, j, ret; int altsetting = -1; + u8 *buffer; tt = kzalloc(sizeof(*tt), GFP_KERNEL); + buffer = kzalloc(5, GFP_KERNEL); rc = rc_allocate_device(RC_DRIVER_IR_RAW); - if (!tt || !rc) { + if (!tt || !rc || buffer) { ret = -ENOMEM; goto out; } + tt->bulk_buffer = buffer; /* find the correct alt setting */ for (i = 0; i < intf->num_altsetting && altsetting == -1; i++) { @@ -283,8 +286,8 @@ static int ttusbir_probe(struct usb_interface *intf, tt->bulk_buffer[3] = 0x01; usb_fill_bulk_urb(tt->bulk_urb, tt->udev, usb_sndbulkpipe(tt->udev, - tt->bulk_out_endp), tt->bulk_buffer, sizeof(tt->bulk_buffer), - ttusbir_bulk_complete, tt); + tt->bulk_out_endp), tt->bulk_buffer, 5, + ttusbir_bulk_complete, tt); tt->led.name = "ttusbir:green:power"; tt->led.default_trigger = "rc-feedback"; @@ -353,6 +356,7 @@ static int ttusbir_probe(struct usb_interface *intf, kfree(tt); } rc_free_device(rc); + kfree(buffer); return ret; } @@ -375,6 +379,7 @@ static void ttusbir_disconnect(struct usb_interface *intf) } usb_kill_urb(tt->bulk_urb); usb_free_urb(tt->bulk_urb); + kfree(tt->bulk_buffer); usb_set_intfdata(intf, NULL); kfree(tt); }