ata: sata_sx4: Add error handling in pdc20621_i2c_read()

The function pdc20621_prog_dimm0() calls the function pdc20621_i2c_read()
but does not handle the error if the read fails. This could lead to
process with invalid data. A proper implementation can be found in
/source/drivers/ata/sata_sx4.c, pdc20621_prog_dimm_global(). As mentioned
in its commit: bb44e154e25125bef31fa956785e90fccd24610b, the variable spd0
might be used uninitialized when pdc20621_i2c_read() fails.

Add error handling to pdc20621_i2c_read(). If a read operation fails,
an error message is logged via dev_err(), and return a negative error
code.

Add error handling to pdc20621_prog_dimm0() in pdc20621_dimm_init(), and
return a negative error code if pdc20621_prog_dimm0() fails.

Fixes: 4447d3515616 ("libata: convert the remaining SATA drivers to new init model")
Signed-off-by: Wentao Liang <vulab@iscas.ac.cn>
Reviewed-by: Niklas Cassel <cassel@kernel.org>
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>

diff --git a/drivers/ata/sata_sx4.c b/drivers/ata/sata_sx4.c
index a482741eb181ffca923519ba7d8ab5e73da1e176..c3042eca6332df4d89862992bb514995a7c3ae25 100644 (file)
--- a/drivers/ata/sata_sx4.c
+++ b/drivers/ata/sata_sx4.c
@@ -1117,9 +1117,14 @@ static int pdc20621_prog_dimm0(struct ata_host *host)
        mmio += PDC_CHIP0_OFS;
 
        for (i = 0; i < ARRAY_SIZE(pdc_i2c_read_data); i++)
-               pdc20621_i2c_read(host, PDC_DIMM0_SPD_DEV_ADDRESS,
-                                 pdc_i2c_read_data[i].reg,
-                                 &spd0[pdc_i2c_read_data[i].ofs]);
+               if (!pdc20621_i2c_read(host, PDC_DIMM0_SPD_DEV_ADDRESS,
+                                      pdc_i2c_read_data[i].reg,
+                                      &spd0[pdc_i2c_read_data[i].ofs])) {
+                       dev_err(host->dev,
+                               "Failed in i2c read at index %d: device=%#x, reg=%#x\n",
+                               i, PDC_DIMM0_SPD_DEV_ADDRESS, pdc_i2c_read_data[i].reg);
+                       return -EIO;
+               }
 
        data |= (spd0[4] - 8) | ((spd0[21] != 0) << 3) | ((spd0[3]-11) << 4);
        data |= ((spd0[17] / 4) << 6) | ((spd0[5] / 2) << 7) |
@@ -1284,6 +1289,8 @@ static unsigned int pdc20621_dimm_init(struct ata_host *host)
 
        /* Programming DIMM0 Module Control Register (index_CID0:80h) */
        size = pdc20621_prog_dimm0(host);
+       if (size < 0)
+               return size;
        dev_dbg(host->dev, "Local DIMM Size = %dMB\n", size);
 
        /* Programming DIMM Module Global Control Register (index_CID0:88h) */