6.18-stable review patch. If anyone has any objections, please let me know.
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From: Sasha Finkelstein fnkl.kernel@gmail.com
commit d579478cee228bdc0029a0c12a1f6a63ea9d1c77 upstream.
Under certain conditions (more prevalent after a suspend/resume cycle), the touchscreen controller can send the "boot complete" interrupt before it actually finished booting. In those cases, attempting to read touch data resuls in a stream of "not ready" messages being read and interpreted as a touch report. Check that the response is in fact a touch report and discard it otherwise.
Reported-by: pitust piotr@stelmaszek.com Closes: https://oftc.catirclogs.org/asahi/2025-12-17#34878715; Fixes: 471a92f8a21a ("Input: apple_z2 - add a driver for Apple Z2 touchscreens") Signed-off-by: Sasha Finkelstein fnkl.kernel@gmail.com Link: https://patch.msgid.link/20251218-z2-init-fix-v1-1-48e3aa239caf@gmail.com Cc: stable@vger.kernel.org Signed-off-by: Dmitry Torokhov dmitry.torokhov@gmail.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/input/touchscreen/apple_z2.c | 4 ++++ 1 file changed, 4 insertions(+)
--- a/drivers/input/touchscreen/apple_z2.c +++ b/drivers/input/touchscreen/apple_z2.c @@ -21,6 +21,7 @@ #define APPLE_Z2_TOUCH_STARTED 3 #define APPLE_Z2_TOUCH_MOVED 4 #define APPLE_Z2_CMD_READ_INTERRUPT_DATA 0xEB +#define APPLE_Z2_REPLY_INTERRUPT_DATA 0xE1 #define APPLE_Z2_HBPP_CMD_BLOB 0x3001 #define APPLE_Z2_FW_MAGIC 0x5746325A #define LOAD_COMMAND_INIT_PAYLOAD 0 @@ -142,6 +143,9 @@ static int apple_z2_read_packet(struct a if (error) return error;
+ if (z2->rx_buf[0] != APPLE_Z2_REPLY_INTERRUPT_DATA) + return 0; + pkt_len = (get_unaligned_le16(z2->rx_buf + 1) + 8) & 0xfffffffc;
error = spi_read(z2->spidev, z2->rx_buf, pkt_len);