From eefe64fba9f2f2328c27ed9d9d02107083a62659 Mon Sep 17 00:00:00 2001 From: Luca Ceresoli Date: Sun, 30 Aug 2020 18:38:49 +0200 Subject: [PATCH] fpga manager: xilinx-spi: add error checking after gpiod_get_value() 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 Reviewed-by: Tom Rix Signed-off-by: Luca Ceresoli Signed-off-by: Moritz Fischer --- drivers/fpga/xilinx-spi.c | 35 +++++++++++++++++++++++++++-------- 1 file changed, 27 insertions(+), 8 deletions(-) diff --git a/drivers/fpga/xilinx-spi.c b/drivers/fpga/xilinx-spi.c index fba8eb4..52aab5a 100644 --- a/drivers/fpga/xilinx-spi.c +++ b/drivers/fpga/xilinx-spi.c @@ -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; + + ret = gpiod_get_value(conf->done); + + if (ret < 0) + dev_err(&mgr->dev, "Error reading DONE (%d)\n", ret); - if (!gpiod_get_value(conf->done)) + 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; } -- 2.7.4