Hello Rui Feng,
The patch c0e5f4e73a71: "misc: rtsx: Add support for RTS5261" from
Oct 21, 2019, leads to the following static checker warning:
drivers/misc/cardreader/rts5261.c:667 rts5261_pci_switch_clock()
warn: impossible condition '(n > 396) => (0-255 > 396)'
drivers/misc/cardreader/rts5261.c
657 pcr_dbg(pcr, "Internal SSC clock: %dMHz (cur_clock = %d)\n",
658 clk, pcr->cur_clock);
659
660 if (clk == pcr->cur_clock)
661 return 0;
662
663 if (pcr->ops->conv_clk_and_div_n)
664 n = (u8)pcr->ops->conv_clk_and_div_n(clk, CLK_TO_DIV_N);
665 else
666 n = (u8)(clk - 4);
^^^^^^^^^^^^^^^^^
667 if ((clk <= 4) || (n > 396))
^^^^^^^
A u8 can only go up to 255.
668 return -EINVAL;
669
670 mcu_cnt = (u8)(125/clk + 3);
671 if (mcu_cnt > 15)
672 mcu_cnt = 15;
673
regards,
dan carpenter
