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fpga manager: xilinx-spi: add error checking after gpiod_get_value()

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Current code calls gpiod_get_value() without error checking. Should the
GPIO controller fail, execution would continue without any error message.

Fix by checking for negative error values.

Reported-by: Tom Rix <trix@redhat.com>
Reviewed-by: Tom Rix <trix@redhat.com>
Signed-off-by: Luca Ceresoli <luca@lucaceresoli.net>
Signed-off-by: Moritz Fischer <mdf@kernel.org>
This commit is contained in:
Luca Ceresoli 2020-08-30 18:38:49 +02:00 committed by Moritz Fischer
parent 16b7856d94
commit eefe64fba9
1 changed files with 27 additions and 8 deletions
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35
drivers/fpga/xilinx-spi.c
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@ -27,11 +27,22 @@ struct xilinx_spi_conf {
struct gpio_desc *done;
};
static enum fpga_mgr_states xilinx_spi_state(struct fpga_manager *mgr)
static int get_done_gpio(struct fpga_manager *mgr)
{
struct xilinx_spi_conf *conf = mgr->priv;
int ret;
if (!gpiod_get_value(conf->done))
ret = gpiod_get_value(conf->done);
if (ret < 0)
dev_err(&mgr->dev, "Error reading DONE (%d)\n", ret);
return ret;
}
static enum fpga_mgr_states xilinx_spi_state(struct fpga_manager *mgr)
{
if (!get_done_gpio(mgr))
return FPGA_MGR_STATE_RESET;
return FPGA_MGR_STATE_UNKNOWN;
@ -57,10 +68,21 @@ static int wait_for_init_b(struct fpga_manager *mgr, int value,
if (conf->init_b) {
while (time_before(jiffies, timeout)) {
if (gpiod_get_value(conf->init_b) == value)
int ret = gpiod_get_value(conf->init_b);
if (ret == value)
return 0;
if (ret < 0) {
dev_err(&mgr->dev, "Error reading INIT_B (%d)\n", ret);
return ret;
}
usleep_range(100, 400);
}
dev_err(&mgr->dev, "Timeout waiting for INIT_B to %s\n",
value ? "assert" : "deassert");
return -ETIMEDOUT;
}
@ -85,7 +107,6 @@ static int xilinx_spi_write_init(struct fpga_manager *mgr,
err = wait_for_init_b(mgr, 1, 1); /* min is 500 ns */
if (err) {
dev_err(&mgr->dev, "INIT_B pin did not go low\n");
gpiod_set_value(conf->prog_b, 0);
return err;
}
@ -93,12 +114,10 @@ static int xilinx_spi_write_init(struct fpga_manager *mgr,
gpiod_set_value(conf->prog_b, 0);
err = wait_for_init_b(mgr, 0, 0);
if (err) {
dev_err(&mgr->dev, "INIT_B pin did not go high\n");
if (err)
return err;
}
if (gpiod_get_value(conf->done)) {
if (get_done_gpio(mgr)) {
dev_err(&mgr->dev, "Unexpected DONE pin state...\n");
return -EIO;
}