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 <hverkuil-cisco@xxxxxxxxx>
Tested-by: Hans Verkuil <hverkuil-cisco@xxxxxxxxx>
Reported-by: Timo Kaufmann <timokau@xxxxxxxx>
Fixes: a284e11c371e ("Input: synaptics-rmi4 - don't increment rmiaddr for SMBus transfers")
Cc: stable@xxxxxxxxxxxxxxx
---
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
