After commit 74d905d2d38a devices requiring the workaround for edge triggered interrupts stopped working.
This is because the "data" state container defaults to *not* using the workaround, but the workaround gets used *before* the check of whether it is needed or not. This semantic is not obvious from just looking on the patch, but related to the program flow.
The hardware needs the quirk to be used before even proceeding to check if the quirk is needed.
This patch makes the quirk be used until we determine it is *not* needed. It is determined as not needed when we either have a level-triggered interrupt or the firmware claims that it has enabled retrigging.
Cc: Andre Müller andre.muller@web.de Cc: Nick Dyer nick.dyer@itdev.co.uk Cc: Jiada Wang jiada_wang@mentor.com Cc: stable@vger.kernel.org Reported-by: Andre Müller andre.muller@web.de Fixes: 74d905d2d38a ("Input: atmel_mxt_ts - only read messages in mxt_acquire_irq() when necessary") Signed-off-by: Linus Walleij linus.walleij@linaro.org --- ChangeLog v1->v2: - Explicitly disable the retrig workaround also if the IRQ descriptor says we have a level triggered interrupt. - Drop the second explicit assigning of "true" to the use_retrigen_workaround bool, it is already enabled. - Augment debug text to say that we leave it enabled rather than enable it. --- drivers/input/touchscreen/atmel_mxt_ts.c | 18 ++++++++++++------ 1 file changed, 12 insertions(+), 6 deletions(-)
diff --git a/drivers/input/touchscreen/atmel_mxt_ts.c b/drivers/input/touchscreen/atmel_mxt_ts.c index e34984388791..c822db8dbd02 100644 --- a/drivers/input/touchscreen/atmel_mxt_ts.c +++ b/drivers/input/touchscreen/atmel_mxt_ts.c @@ -1297,14 +1297,18 @@ static int mxt_check_retrigen(struct mxt_data *data) int val; struct irq_data *irqd;
- data->use_retrigen_workaround = false; - irqd = irq_get_irq_data(data->irq); if (!irqd) return -EINVAL;
- if (irqd_is_level_type(irqd)) + if (irqd_is_level_type(irqd)) { + /* + * We don't need the workaround if we have level trigged + * interrupts. This will just work fine. + */ + data->use_retrigen_workaround = false; return 0; + }
if (data->T18_address) { error = __mxt_read_reg(client, @@ -1313,12 +1317,13 @@ static int mxt_check_retrigen(struct mxt_data *data) if (error) return error;
- if (val & MXT_COMMS_RETRIGEN) + if (val & MXT_COMMS_RETRIGEN) { + data->use_retrigen_workaround = false; return 0; + } }
- dev_warn(&client->dev, "Enabling RETRIGEN workaround\n"); - data->use_retrigen_workaround = true; + dev_warn(&client->dev, "Leaving RETRIGEN workaround enabled\n"); return 0; }
@@ -3117,6 +3122,7 @@ static int mxt_probe(struct i2c_client *client, const struct i2c_device_id *id) data = devm_kzalloc(&client->dev, sizeof(struct mxt_data), GFP_KERNEL); if (!data) return -ENOMEM; + data->use_retrigen_workaround = true;
snprintf(data->phys, sizeof(data->phys), "i2c-%u-%04x/input0", client->adapter->nr, client->addr);