Messages in this thread | | | From | Ed Vance <> | Subject | RE: Serial.c BUG 2.4.x-2.5x | Date | Mon, 18 Mar 2002 16:16:57 -0800 |
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On Thu Mar 07, 2002, Roman Kurakin wrote: > > On Wed Mar 06, 2002, Russell King wrote: > > > >The patch does fine for the most part, but I have two worries: > > > >1. the possibilities of pushing through changes in the IO or memory space > > by changing the other space at the same time. (ie, port = 1, iomem = > > 0xfe007c00 and you already have a line at port = 0, iomem = 0xfe007c00). > > I dealt with this properly using the resource management subsystem. > > > I think such code could solve this problem ... > > - (rs_table[i].port == new_port) && > + ((rs_table[i].port && rs_table[i].port == new_port) || > + ((rs_table[i].iomem_base && rs_table[i].iomem_base == new_mem)) &&
Indeed it would solve this problem, but I'm not sure there is a problem to solve here. Have not found a case where ->port and ->iomem_base fields can both be non-zero. If one of them is always zero then the previous patch hunk in the "address in use" test at about line 2146 is well enough:
if ((state != &rs_table[i]) && (rs_table[i].port == new_port) && + (rs_table[i].iomem_base == new_mem) && rs_table[i].type) return -EADDRINUSE;
Assuming one of the two fields is always zero, demanding both to match for the in use condition works anyway. If the non-zero field matches, then they both must match. The following hunk at the bottom of function get_pci_port() at about line 3931 seems to guarantee that they start out this way:
[[ The req struct is memset() to zero at about line 4009 in function start_pci_pnp_board(). ]]
if (IS_PCI_REGION_IOPORT(dev, base_idx)) { req->port = port; if (HIGH_BITS_OFFSET) req->port_high = port >> HIGH_BITS_OFFSET; else req->port_high = 0; return 0; } req->io_type = SERIAL_IO_MEM; req->iomem_base = ioremap(port, board->uart_offset); req->iomem_reg_shift = board->reg_shift; req->port = 0; return 0;
Does anybody see a need to add the code anyway? Did I miss a lurker?
Best to all,
---------------------------------------------------------------- Ed Vance serial24@macrolink.com Macrolink, Inc. 1500 N. Kellogg Dr Anaheim, CA 92807 ----------------------------------------------------------------
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