[PATCH for v5.5 2/2] Input: rmi_f54: read from FIFO in 32 byte blocks
From: Hans Verkuil <hidden>
Date: 2020-01-15 12:48:27
Also in:
linux-media, stable
Subsystem:
input (keyboard, mouse, joystick, touchscreen) drivers, the rest · Maintainers:
Dmitry Torokhov, Linus Torvalds
The F54 Report Data is apparently read through a fifo and for
the smbus protocol that means that between reading a block of 32
bytes the rmiaddr shouldn't be incremented. However, changing
that causes other non-fifo reads to fail and so that change was
reverted.
This patch changes just the F54 function and it now reads 32 bytes
at a time from the fifo, using the F54_FIFO_OFFSET to update the
start address that is used when reading from the fifo.
This has only been tested with smbus, not with i2c or spi. But I
suspect that the same is needed there since I think similar
problems will occur there when reading more than 256 bytes.
Signed-off-by: Hans Verkuil <redacted>
Tested-by: Hans Verkuil <redacted>
Reported-by: Timo Kaufmann <redacted>
Fixes: a284e11c371e ("Input: synaptics-rmi4 - don't increment rmiaddr for SMBus transfers")
Cc: stable@vger.kernel.org
---
drivers/input/rmi4/rmi_f54.c | 43 ++++++++++++++++++++++--------------
1 file changed, 27 insertions(+), 16 deletions(-)
diff --git a/drivers/input/rmi4/rmi_f54.c b/drivers/input/rmi4/rmi_f54.c
index 0bc01cfc2b51..6b23e679606e 100644
--- a/drivers/input/rmi4/rmi_f54.c
+++ b/drivers/input/rmi4/rmi_f54.c@@ -24,6 +24,12 @@ #define F54_NUM_TX_OFFSET 1 #define F54_NUM_RX_OFFSET 0 +/* + * The smbus protocol can read only 32 bytes max at a time. + * But this should be fine for i2c/spi as well. + */ +#define F54_REPORT_DATA_SIZE 32 + /* F54 commands */ #define F54_GET_REPORT 1 #define F54_FORCE_CAL 2
@@ -526,6 +532,7 @@ static void rmi_f54_work(struct work_struct *work) int report_size; u8 command; int error; + int i; report_size = rmi_f54_get_report_size(f54); if (report_size == 0) {
@@ -558,23 +565,27 @@ static void rmi_f54_work(struct work_struct *work) rmi_dbg(RMI_DEBUG_FN, &fn->dev, "Get report command completed, reading data\n"); - fifo[0] = 0; - fifo[1] = 0; - error = rmi_write_block(fn->rmi_dev, - fn->fd.data_base_addr + F54_FIFO_OFFSET, - fifo, sizeof(fifo)); - if (error) { - dev_err(&fn->dev, "Failed to set fifo start offset\n"); - goto abort; - } + for (i = 0; i < report_size; i += F54_REPORT_DATA_SIZE) { + int size = min(F54_REPORT_DATA_SIZE, report_size - i); + + fifo[0] = i & 0xff; + fifo[1] = i >> 8; + error = rmi_write_block(fn->rmi_dev, + fn->fd.data_base_addr + F54_FIFO_OFFSET, + fifo, sizeof(fifo)); + if (error) { + dev_err(&fn->dev, "Failed to set fifo start offset\n"); + goto abort; + } - error = rmi_read_block(fn->rmi_dev, fn->fd.data_base_addr + - F54_REPORT_DATA_OFFSET, f54->report_data, - report_size); - if (error) { - dev_err(&fn->dev, "%s: read [%d bytes] returned %d\n", - __func__, report_size, error); - goto abort; + error = rmi_read_block(fn->rmi_dev, fn->fd.data_base_addr + + F54_REPORT_DATA_OFFSET, + f54->report_data + i, size); + if (error) { + dev_err(&fn->dev, "%s: read [%d bytes] returned %d\n", + __func__, size, error); + goto abort; + } } abort:
--
2.24.0